Maybe the non-stop vitriol, hatred, and death threats have something to do with it?

Humans have an incredibly powerful coalition instinct. Get hated by a coalition and it takes a saint not to end up in a coalition that's in opposition.

Wait, no, aren't saints in a coalition with God against Satan?

Anyway, I'm not sure that this is what happened. But if you take JKR at her word in June 2020, it's got to be pretty high on your list of explanations, no?

If you don't take her at her word in June 2020, I'm not quite sure why you're asking the question in this way.