Fascinating take...
So according to this line of thinking, usury religious laws served as a sort of fiscal "stablizer" for the people of antiquity before secular standards could be set up to prevent gross abuse by creditors and debtors alike?
That's it. Anti-usury laws, and a disdain for merchants in general, is a necessary trend to conciliate the poor majority from becoming so desperate they rebel and set up their own new regime. To the extent that a certain amount of social ferment of this type always exists, this has actually been what has happened. As others say, the Hebrews got their notions from experience. "Remember you too were once slaves in Egypt!"
As the Roman example shows, it is not necessary to make sweeping and absolute prohibitions; regulation can do. But something along these lines is necessary.
At least until modern capitalist civilization arose anyway. Even we have some rules.
Prior to capitalism, the balance of productive activity was primary agriculture and craft work, most of it subsistence level. Communities could only afford to alienate a small portion of their overall product for trade. Traders were therefore generally seen as somewhat alien, or completely so, and in terms of idealizing philosophers, not strictly necessary. A civilization that normalizes trade as the basis of natural existence required a certain substrate of development to make it possible, and then a reversal of notions common to all preceding civilizations to complete the normalization.
So the prohibition on usury, in its core sense, is no mere fluke of a peculiar people happening by sheer chance to lay foundations for two world-conquering religions. I think of Islam as in fact a merchant's religion, founded by and spread by merchants, and in many ways it does normalize trade--in part by regulating it by moral admonition. Without that it could not spread the pro-mercantile aspects it does. With regulation, or at least the principle of it enshrined, it does permit sophisticated financial development--just along different principles than European usury-in-defiance-of-ancient-law. I have been struck by how many passages of the Koran resemble the laments of the Hebrew prophets denouncing the callous treatment of the poor by the powerful, who should consider their privilege a gift from God and a responsibility to do right with their power. I don't think Mohammed was merely mimicking a style he'd picked up; he was reacting spontaneously much the way the the old prophets were, and finding mass support among common people thinking much the same way that he helped them articulate clearly; rather than being some random offshoot of the Hebrew texts, he embraced them for the good sense of their contents.
And even in the modern European tradition, adoption of practices clearly denounced by the old Christian Fathers of the Church had to go hand in hand with the rise of a concept of human rights and democratic governance, which tends to countervail the worst tendencies of what economics professors teach to be mere "rationality."
Regarding that last clause, it explains comments such as one high up the thread that assumed absence of a mere superstition against usury would spell faster progress. I don't think it is possible, and if it were I doubt progress would be faster.