From a societal and biology/evolution standpoint, it would seem that pissing off your enemies is a very bad survival strategy, yet huge numbers of humans derive gratification from it and the very existence of the trolling pastime proves that it’s pleasurable enough for its own sake. Trump supporters get joy from “pissing off the libs” and vice versa. Is it merely because, nowadays, in the Internet and modern era, that most people face no real danger from pissing off those with opposing views? (I imagine that, if one is in a Rwandan Hutu vs. Tutsi situation, that the idea of pissing off an opponent who wields machetes quite near you suddenly loses its appeal.)
What’s the evolutionary purpose of getting pleasure from stoking up your enemies’ anger?
It’s not “pissing off,” it’s an attempt at intimidation. If you behave aggressively towards others, whether physically or verbally, you may scare them into putting up less resistance, or deter them from attacking you.
I’m not sure “intimidation” is what it’s about (which seems to imply “cause fear”) - when people on the Internet share memes meant to mock and anger the “other side,” it doesn’t seem to be about causing fear but rather just anger. The “U mad bro?” approach, poking them with a verbal stick.
We didn’t evolve with the internet. As you speculate, the fact that we now face no consequences for this behavior makes it more prevalent. We take pleasure in acts intended to intimidate because at one time that was adaptive behavior.