Democratic Socialism is a contradiction in terms.
This is just you citing a dogma that I suppose you believe in. Many other people can easily conceive a democratic socialism. Indeed if one says one is a socialist not in the sense of demanding that society must immediately conform to all the goals one has as a socialist, right now, but is prepared to compromise for now with existing anti-socialist institutions in the patient faith that over time, in a democracy anyway, the socialist view will prevail as the best, then there are legions of democratic socialists at this very moment. Your claim they cannot exist is not going to be very impressive to them, not to me for instance.
Now then in your argument do you connect this sweeping claim with the question at hand here in this thread, or adduce hard evidence to justify your sweeping claim?
If the government/revolutionary movement has enough power to expropriate property and murder "capitalists" without a trial (or a least not prosecute anyone who does), why would the neo-Jacobinist revolutionary leaders magically accept the constraints on the power that would be expected in a liberal democracy?
It's pretty unrealistic to expect a government that emerges through a bloody revolution and civil war to turn around and setup a working parliament with a reasonable degree of human rights.
So then, would you say the American Revolutionary War was bloodless and had no elements of a civil war? How about the war we call the Civil War, which seems to have been absolutely necessary to establish such principles as race being irrelevant to political rights, and laid the groundwork for most of what we take for granted as Federal guarantees of our human rights today? Note that prior to the Reconstruction Amendments the Bill of Rights itself was deemed to apply solely to restricting the Federal government, leaving adherence to or abrogation of its principles up to the political consciences of the various states. It is only such things as the expansion of the principle of "equal protection under the law" that underlies a lot of the civil rights we take for granted today--and there are people who argue the Federal government has overstepped its bounds and these alleged grounds and even alleged rights should not be honored, or anyway not enforced at a Federal level on all states.
Your use of the word "Jacobin" is quite interesting. Actually, in their radicalism, the Jacobins were the liberals of their day, in an age when a decidedly pre-liberal sentiment ruled their foes. Do you not realize that liberal parliaments, and legislatures in general since we Yanks don't have parliaments, are in fact generally precisely the outcome of some bloody revolution and civil war? That it is quite doubtful the British Parliament as we know it would exist without Cromwell's Commonwealth? Do the French of today doubt that they owe their freedom and their democracy to the risings of 1789 and the subsequent turmoils of the First Republic? (I have reason to think some do; I remember reading an essay in Time or Newsweek back in the appropriate week of Bastille Day, 1989, the 200th anniversary of that event, by some French person purporting to believe the Revolution was some kind of mistake. Indeed we live in an age when anti-democratic reaction is on the rise, which I attribute such views to. To any democrat, and especially a liberal one, the events of the 1790s may hold horrors but they were also clearly the birth of a new France, and a new Europe, and only in this revolutionary Europe does the concept of the Rights of Man hold any sense. The "ultramontane" reactionary faction of Roman Catholic leadership ranted against it for a full century and more, only coming round to accepting the new liberal order in the papacy of John XXIII.
So your conflation of liberal democracy and human rights with abstention from bloody revolution and avoidance of civil war seems incredibly quaint and complacently ignorant of the processes of history. We would not be here talking about human rights without revolution, and indeed every advance of the concept of human rights--and I have seen a lot of progress in my lifetime--comes from people challenging the established order, not meekly complying with it. It may be indeed that when we have a liberal democracy that revolutionary violence is never then in order; take it up with Abraham Lincoln. I think he and I would agree that perhaps my reference to him is moot since he was opposing illiberal anti-democracy.
But your grasp of historic fact seems to have other gaps in it too. Who do you think instituted the soviets the OP is talking about, and when? It was not the Bolsheviks who invented them!
Nope, the first soviets in the sense we are talking about--for it is just a word that means "council" in Russian and various types of "soviets" had existed over centuries of Tsarist rule--were invented by working people in the 1905 uprisings in the wake of the defeat of Tsarist forces by the Japanese, including such incidents as the revolt of the crew of the battleship
Potemkin celebrated in the famous Soviet movie. This was 1905, not 1917, and I believe the Bolshevik faction had not even formed in the Russian Social Democratic party yet, or if it had it was quite new. The Bolsheviks had few agents on the ground, the Tsarist police having arrested and exiled or imprisoned most of them. By 1917 there were a lot more because Bolsheviks, being largely recruited from industrial workers, were often sent into artillery units in the Great War and as the defeat of the Russian forces became more and more manifest, they propagandized and recruited large numbers of their fellow soldiers, first in the artillery units and then more broadly. But in Petrograd, they had a limited footprint.
Indeed the Bolsheviks celebrated and admired the formation of soviets again in the wake of the
February Revolution. But note the eight month gap between the successive Revolutions of 1917 in Russia. For that long period, the various soviets of Petrograd, Moscow, and other more or less industrialized cities of Russia were very much in the democratic hands of diverse working class Russians. One reason the Bolsheviks admired the soviets was precisely the fact that they did not create them, that the Russian people had invented them spontaneously. I think that spontaneity definitely had something to do with the influence of a generation of would-be revolutionaries propagandizing the masses, but the point is that these were not imposed by some clique of fanatics at the point of a gun; in the context of the common Russian workers' political understanding, forming these councils was the obvious thing to be done. They derived no power from any authority above them; they were the direct and grassroots expression of the democratic spirit of the Russian urban masses.
Another thing they were and did probably relates more cogently to your deploring revolutionary violence--I don't know about your heritage because who can tell what background a person here has except their own say so, but as an American such head shaking seems to denounce my heritage, since my nation was founded precisely on revolutionary violence that included expropriations; I am not sure how many "Tories" were actually killed by American revolutionary Patriot "mobs" but I do know many fled for their lives to avoid being so killed. It is a thing that happens in revolutions.
But I am pretty sure the soviets did not immediately start raiding the homes of their employers and ransacking them. What they did that might, perhaps, seem criminally offensive to some, is organize their councils in their workplaces. This is where most industrial working class people spend most of their waking hours, under the direction of their capitalist bosses. It was their center of power therefore and they took over their shop floors, presuming to claim authority over its operations as well as their share of civil government.
In the context of 1917 Petrograd and other major Russian industrial centers, it was indeed unlikely a suitably liberal regime to your sensibilities would be enacted by will of the people. Not only the common people but the Tsarist-regime-serving intelligentsia (such as what most Mensheviks were, such as what the lawyer Kerensky, who litigated on behalf of the Social Revolutionaries, non-Marxist agrarian radicals, was) were radicalized in some degree; very few people thought a conservative form of liberalism as you might approve was on the agenda in Russia. The ones who rejected revolutionary radicalism of some kind were frank authoritarians and monarchists, there were no liberals of the type you might like, unless you openly would like a limited franchise of the well propertied only, which had some support--among the numbers of well propertied, by some strange coincidence. But even many of them, like the Mensheviks, who were parlor Marxists, or people like Kerensky, felt the wave of the future in Russia was going to be more radical than anything known to the governments of western Europe in the Belle Epoque. It was a question of which radicals, and how radical.
So, the Soviets were the Russian street and shop floor. They were the vast majority of the people in these cities. They organized councils, based in their workplaces, which would presume to control both the workplace and the region of the city around them, and would cooperate with other neighboring councils, and formed a City Soviet, which was composed of delegates sent by the various factory soviets. I do not believe, in the eight months between the February Revolution which swept away Tsarist police power (indeed according to some accounts, the police who did not escape were dead men, despised by all--the public slang for them was "Pharaoh" in reference to the whip-wielding oppressors as Exodus portrayed the hostile new dynasty against the Hebrews). It was militia of the soviets who policed the streets maintaining order, and decisions were, as I understand it, not permitted to happen by spontaneous mob rule but only on order of soviets after due deliberation. The army remained organized, indeed Russia was still at war with Germany (and still losing) but the soldiers would take orders from the self-proclaimed "Provisional Government" only if countersigned by the city Soviet. The soldiers thus clearly accepted the Soviet and not the PG as the basis of what authority the Russian government had. The soviet system, in this inter-revolutionary sense of a federation of local grassroots democratic worker's councils, was that government. It was decisions by the Soviet that determined what Russians would do in the name of their state, except for an elite clique that looked to the PG for direction. But the Provisional Government had no particular basis of authority beyond the general sense of the better off classes in Russia that they needed someone to protect them from the mob, and the fact that their European allies in the Great War were impressed with their appearance of regular legitimacy. But the Russian people had denounced and effectively put the Tsar under house arrest, denying their ongoing allegiance to him. The PG debated and considered trying to instal a new Tsar, discussing several candidates, but the people of the street would have none. Whatever Russia was to become, if the people had their say it would not be a monarchy again, not even a constitutional one.
I believe in the eight months of what Marxist historians such as Trotsky called "Dual Power," the city Soviet guaranteed the kind of order that protected the propertied from gross outrages, and the question of ownership of their assets and their effective control of them remained up in the air. It was only after the Bolsheviks organized a violent coup that took down the last bastions of anti-soviet power and also straightjacketed the soviets into complicity with the Bolshevik line--which did enjoy popular majority support in most soviets by this time, in Petrograd anyway--that the sorts of things the OP thought might happen and that you denounce started happening, under Bolshevik Party direction.
Now was some sort of dictatorial revolutionary takeover inevitable, and if there was an alternative, was it anything but the restoration of authoritarian reaction as had prevailed in Russia before the Tsar did so much to start the Great War that ultimately destroyed him?
I think we'd need a POD well before 1917, establishing the authority of more moderate revolutionaries than the Bolsheviks in the cities, which means someone appealing to the industrial workers in a way that satisfied them.
If we stipulate not the crushing of all popular democracy but a balance of power between the radical factions, I think the soviet system could have simply brushed aside the PG and been established as the republican form of Russian government. It would not be parliamentary or formally follow the American model either. But so what? Why is democracy as such limited to these specific forms? Instead of people voting every two or four or five years for some of their leaders, continual grassroots town meeting style face to face direct democracy would hold and implement power directly on the local level, and above the heads of these councils, they would appoint councils coordinating the local ones composed of delegates sent by the various grassroots ones, and then as many levels as needed would be created to span the entire nation. It would be democratic republicanism in the sense that the local councils would be the center of power, and these would be directly democratic, but protocols of federal cooperation would form via the higher councils, which would have a membership ultimately drawn from the grassroots soviets.
With some important differences to be sure, I think it most resembles the Swiss system. Would you deny Switzerland is possible? There it sits in the Alps. And do you think its history was free of revolutionary violence? Read up on it and get back to us, you might be surprised!