Gamergate from the very beginning was a 4chan psy op, one of the most successful in history.
Here's an old effort post I made on it awhile back.
So, Gamers. The big capital G. We have had a very, very interesting relationship with politics since the very beginning, when we got blamed for mass shootings from people on both sides of the aisle . This made the gaming subculture very, very wary of government intervention from the early days. This continued for quite some time, into the 2000s with the likes of Jack Thompsan and Leeland Yee. People who wanted to ban games outright. People that were legitimately ignorant and deserve all the scorn thrown their way. Games were a very easy target for a very long time.
Fastforward to 2014. This has been simmering under the surface for a very, very long time, and with the advent of Youtube, its about to come to the surface. Its worth noting this is about the time that the fear of "Sjws" began popping up on the internet, with subs like /r/tumblrinaction being the HQ of these places. Some people legit deserved mockery, and on the other end.. they laughed at women with pink hair. It was a very, very weird time. This was two years after Anita had posted her kickstarter for her youtube series which uh… offended gamers by looking at games through the eyes of feminism? Now, I have a theory as to why gamers reacted so strongly to this. They viewed this as outside critique. The same outside critque that had for years threatened their medium with literal extinction at the hands of the US Governemnt and Mainstream Meida.
These two subcultures shared a not insignificant overlap, but nothing really boiled over, until "theZoePost"
On August 15th, 2014, shortly after the steam release of Zoe Quinn's well received "Depression Quest", her ex-boyfriend went online and accused her of cheating on him during their relationship. Nevermind that this is a really trashy thing to do, your really shouldn't be airing your dirty laundry in the public like this. Those posts were deleted from the site he put them on, and he was banned. In retaliation, he posted an edited version of the post on his blog. He stated in this blog post that the entire point of this post was to appeal to those who already hated Quinn, to give them more amunition. It worked, and it inspired doxxing, her Email, Cloud Hosting, and Social Media accounts all being compromised and nudes being leaked. Those nudes were sent to her family and place of employment.
Of course, the 4channers who started this in the IRC channel #burgerandfries needed a justification, something to give them a cause to rally behind. One of the alleged people that Zoe Quinn had cheated on her ex with was an IGN reviewer, who had, in fact, gave "Depression Quest" a positive review. At least, thats what they claimed.
There was just really one problem. The IGN reviewer in question, Nathon Grayson, never wrote anything about Depression Quest. In fact, the only time he had ever covered Quinn before was covering her failed reality show. So they moved the goalposts, and claimed that he had given her positive press in another publication, Rock Paper Shotgun, FAR before any of the accused cheating happened. But it didn't matter that these were true. Anti-SJW youtubers, eager for content at the time, ATE THIS SHIT UP, only increased in their frenzy when the mods of /r/gaming, the biggest gaming subreddit, deleted all mentions of the "controversy'
Sources:
http://www.wehuntedthemammoth.com/2014/09/10/spamming-doxxing-and-sockpuppeting-4channers-dirty-tricks-straight-from-their-irc-log/
https://arstechnica.com/gaming/2014/09/new-chat-logs-show-how-4chan-users-pushed-gamergate-into-the-national-spotlight/
http://www.wehuntedthemammoth.com/2014/09/08/zoe-quinns-screenshots-of-4chans-dirty-tricks-were-just-the-appetizer-heres-the-first-course-of-the-dinner-directly-from-the-irc-log/