A group of people perceived a reporting bias in most video game websites, that things that were "Social-Justice"-y got undue positive press. A chick who made a "Social-Justice"-y "game", who got some pretty good press for said "game", turned out to have fucked someone who had written articles with her "game" in them. These articles presented her "game" pretty positively.

When this hit the social news sites, it was censored under the claim that it was misogynistic to go after her for it, because it was her private life. Because this was a month after it wasn't Max Temkin's private life when someone passively accused him of rape, people saw that as confirmation of the bias.

With this confirmation of bias in hand (among other catastrophically idiotic things that would happen later), the group managed to attract a fairly large following. That group became "Gamergate", /r/KotakuInAction, etc. They have since done various things in addition to arguing about videogames, like getting advertisers to pull support for various websites for ethical violations, and possibly contributing to various writers leaving the websites they wrote for.

Honestly, it persists as well as it does because the websites and people it opposes continue to do catastrophically idiotic shit.

"Anti"GamerGate (/r/Gamerghazi, not /r/againstgamergate) is a group that has fixated on the perceived reactionary elements of Gamergate, and has acted much like you would expect an SRS-like group to act.

I have tried to remain unbiased in that blurb, personally I find both sides of the gamergate debate/arguement/clusterfuck to be a bit fucked in the head. Shit websites were shit before this happened, and they remain shit, and the only really good thing to come of all this is that more people know those websites are shit.