The issue with PUAs is that they operate on the principle that men can't win unless women lose. By injecting a zero-sum philosophy into a win-win situation, they create an atmosphere of antagonism and distrust. But that's just generalist speaking. They're also assholes to women and substitute a desire for learning and understanding for a desire for domination and denigration. There are bad actors on both sides of the dating aisle but as one side is responsible for the lion's share of violence, abuse and revenge porn, pointing to a handful examples of spiteful women can only invite a torrent of counterexamples - I mean, yeah. A girl at Duke put together a catty powerpoint. She didn't stab her roommates and shoot up a fraternity.
PUA is perhaps a very specific term. I just know some womanizers, with an overall genuine respect for women and who seems more 'used' than the other way around. I suspect in normal life PUAs are like that. They just put up a macho facade, because the net is what it is. I mean, the dude offered all his benefice to the local rape-awareness-charity once he got called upon. And the girls seems to like him -before they learned he was ranking them-. Is nastyness seems a fruit of vanity; proud born from his 'sucess'.
There are people who wear the PUA label with pride, and they're generally problematic in mixed company. And yeah - PUAs might be "normal" in real life... but they sure can stink up the Internet. Nastiness you don't know about is all the worse when you do.