>The site remained on the fringes until 2014, when some supporters of GamerGate — a loose reactionary collection of anti-feminist video gamers — flocked to 8chan after being kicked off 4chan. Since GamerGate, 8chan has become a catchall website for internet-based communities whose behavior gets them evicted from more mainstream sites.
It may be argued that 4chan’s existence gave a home to this crap, or that it created it. Hard to know one way or another.
4chan was created by somethingawful users as an imitation of Japanese imageboards. It was used for speech that wasn't allowed on SA because it was right next door. Then SA decided it didn't like 4chan.
Then SA's culture spread to magazines like Gawker and Buzzfeed, which is part of the reason 4chan is so unpopular now.
If Gawker and Buzzfeed had hired from one side of the Harry Potter fandom, and if a handful of high-profile people like Zoe Quinn had come from it, we'd probably be hearing about how all of America's problems are caused by people who like Snape or whatever.