

I’d argue it happens just as much in right wing spaces. People with soap boxes want to make sure nobody listening to them will rebuke them.
It’s small people in big spaces. People want to feel secure and reassured in their feelings. Presently, it may seem as though left leaning spaces use these purity tests more frequently but I would argue that’s the result of under-representation in modern politics.
Many left leaning folks have to vehemently defend the feelings they hold in their hearts. Meanwhile right wing folks get to say “I feel what I feel! You know in your hearts it’s the moral thing to do! Anyone who opposes is immoral”
So, you end up with a lot of leftists who have to carve out safer spaces for conversation. I think, because the societal default opinion for leftists is that they hold immoral stances. ie: socialists, communists, anarchists. They seem evil to outsiders.
Right, but now go say some lightly left leaning things in one of those communities and watch the vitriol roll in.
Like I said, little people, big internet.