Sorry, but i don't have as much faith in mankind as you, anti-semitism was common throughout europe, if germany could do it i'm sure there is a timeline where france did it.
Beside, if you switch the victims from jews to algerian muslims, you can definitely find a way for france to commit a holocaust scale genocide with a 1900 POD in algeria.
It isn't that the French are uniquely good or angels, just that there are reasons why holocausts and genocides happen, and the French have less triggers and less capability to act on those triggers than the Germans did.
The problem with colonial holocausts is that the colonial power is dependent upon the colonized population to provide for the livelihood and the value of its colony. If one kills all of the colonized people then the colony ceases being useful. The only time when this actually makes sense is in a settlement colony, like the British and American genocides in North America and Oceania. Algeria was a settlement colony, but the native population was very large and useful to the French. One can easily see extreme repression, vast amounts of loss of life, famines, etc. but an actual full-scale genocide of the population intended by the French is unlikely, even if there were "jokes" that all that it would take for the French to solve the Algerian problem would be to give every Algerian settler a pistol and 9 bullets.
Of course, you could simply be referring to a policy of famine and colonial repression, responsible for the deaths of millions in British India as one example, and which had themselves killed huge numbers of Algerians such as during the 1870 revolt. But that is much more mundane for colonialism and generally a byproduct of colonial policy rather than being the intent.
Action Francaise + Black Hundreds = Holocaust. It's not that hard a calculation.
Pogroms alone killed 150,000 people in the period from 1918-1922. In prior pogroms the rioters would be encouraged by the secret police and given clemency by the Tsar. The difference is that Russian slaughter of Jews would be more like the Rwandan Genocide than the Holocaust.
Charles Maurras of Action Francaise was very very Hitler-like. He founded AF in response to the Dreyfus affair and blamed the whole thing on the Jewish Republic. In the 1920s he condemned Versailles for not being harsh enough, called for killing an Interior Minister (who was Jewish and wanted right-wing leagues disarmed), and was sent to prison for 8 months by issuing death threats against Leon Blum.
Maurras also thought that the 1940 Statutes on Jews was too moderate. These would be the laws that denaturalized Jews as citizens, and excluded Jews from the army, press, commercial and industrial activities, and the civil service. In 1940 40,000 non-French Jews (refugees/migrants) were interned. Then in 1941 the government required registration of Jewish businesses and excluded Jews from any commercial or industrial profession.
Petain's Chief of Staff after the war said that "Germany was not at the origin of the anti-Jewish legislation of Vichy. That legislation was spontaneous and autonomous."
Action française was a tiny minority of the French political system with no real power. They had no chance of gaining power outside of being installed by foreign bayonets and any foreign power is going to choose somebody who is more useful to them than a glorified fringe group. It is comparable to say, the US Libertarians as something of comparable size and influence, and it is like them making an argument for something and 20 years from now this being decided to be atrociously evil, so the Libertarians would be put under historical spotlight and examination just as Action française is magnified to examine the French strain of antisemitism in the context of the Holocaust. There is a big difference between advocating for that and actually being able to gain power. Even if they do win power, there is a great difference between purging the Jews from government, enforcing harsh and discriminatory laws against them, stripping them from public functions, confining them to ghettos, revoking their nationality, etc. and actually proceeding to a Holocaust. Even for the Germans it took a very substantial period of time to actually escalate to the Holocaust, the better part of a decade.
As far as I am aware in Vichy's colonies they never went as far as actual killing, and so I am inclined to believe that Vichy's internal measures, while doubtless of their own volition, inherently had inspiration and a model in the German ones.
Even in a lost-WW1 scenario, which is not allowed in this thread, Action française is less likely to gain control of government than other parties, since they are rather elitist, have a tradition of being quite incapable of compromise, and were to my understanding rather poor at the actual business of winning elections. I would compare it to the DNVP in Germany for their best trajectory: extreme, often violent, destabilizing, and capable of winning some votes, but not enough to actually upset the system.
