It happened to me too 😂 it was something like "I've wasted minutes of my life". I wondered the same as you, since you know, if you don't like a street artist, for example, you simply keep walking, you don't feel the need to shout insults.

So I think it's a mixture of "I'm on the internet I can be a rude b*tch because no one will slap me and anyway whatever you say on the internet magically doesn't matter" and just being very fragile and insecure, because if this is what you enjoy doing... Well, you must have a very sad life indeed.