What's most interesting about the article is that it manages to completely skip over why it was extremely useful for medieval notions of usury to not apply to Jews. Specifically, anti-Semitism was so widespread that it was socially acceptable for someone powerful to borrow money and decide to kill or expel their counterparties afterwards.
Which is to say notions of usury served to legitimize theft from outsiders. The rest is a shocking amount of window-dressing and apologetics.
In a way, that's not relevant to the point being made. "X is a sin/bad thing" is not made less true by "X has occurred", "X has been used by political powers", or "even people who agreed X is a bad thing have put great effort into finding ways to do it anyhow".
I posted this because in the modern world, "usury is a particular and bad thing" is a fresh viewpoint, and yet, one that a lot of people here may find themselves quite sympathetic to. The idea that student loans are really getting into "indentured servitude" levels of exploitativeness is in the air, and it turns out that rather than a novel observation, it's actually an ancient one, and it can be helpful to "cheat" on some of the debates and understandings by reading the end of the book instead of trying to start from scratch.
You're absolutely right. Usury as sin is not in any way a novel idea. You are also unquestionably correct that it can be helpful to learn from the past on the subject!
Is it perhaps possible that some might opine that the historical context of an idea is worth knowing as part of reading the end of the book? It just might be worth considering that the historical implementations of policy around usury could not be divorced from the abstract reasoning.
In a way, it's like discussing historical Communism and Communist thought while pretending Stalin, Lenin, and Mao never existed. They all form part of the historical context that really needs to be considered an integral part of the whole.
Again, you're completely correct. There's a great deal to be learned from history!
Which is to say notions of usury served to legitimize theft from outsiders. The rest is a shocking amount of window-dressing and apologetics.