It used to just be x-ism, with the subset specifically of "benevolent x-ism" getting named to explain to people how words that are meant to be kind are also damaging. Bigotry of low expectations is the most well known example of that. If you believe these things exist and were a problem, it was a genuinely helpful term for that.

Adding the hostile label to it is just lazily adding an emotional angle to it because they know x-ism has been overused to the point of people not caring about it.