It has roots in absurdism.
See, blogs with a lot of followers usually have mutuals. And one day, it became a joke among friends to, in response to a friend making horny posts or bad posts, to respond in an exaggerated manner like 'Izzy I swear to god I'll break your fucking wrists'. The mutuals had a good laugh, the leech followers thought it was funny, and reblog variations of things like this.
Unfortunately, unfunny children take this joke among friends as stealable humor and now leave comments like 'OP I'm going to doxx you, break into your house and scoop out your eyeballs' on a joke post about the hamster from Overwatch dating D.VA
because haha it is a joke! despite how it's a giant overstep for people who don't know you and never asked for you on their post
Now this cycle of 'fake violence' is repeated all over posts to the point that you can't tell who is sincere and who is 'jokeposting' and it's all very unfunny and painful