Gamers are a demographic interested in certain topics who buy stuff. Thus, magazines and websites staffed by professional journalists are created to carry articles that interest those people and ads selling stuff that they are likely to buy.
Gamer journalists are, being journalists, extremely politically correct, and make it their mission to morally improve their audience and make them as holy as their extremely holy selves.
Gamers are anonymous, therefore free to be politically incorrect. Further, they are customers, hence game developers really have to give them what they want, rather than what the politically correct think the gamers should receive. Thus games tend to be full of stereotypes.
World of Warcraft’s Africa (Stranglethorn vale) contained a Great Zimbabwe that was ugly, primitive, and long been abandoned by the simple minded cannibal savages native to the area. Who, by the way, cannot speak very well, because they are pretty much mentally subnormal.
The Warcraft religion of light was ninth century Christianity with the serial numbers filed off, and all its leading figures were noble, heroic, kindly, and, apart from the tendency to bash evildoers with big hammers, Christian. Which not only depicted Christianity in a good light, but implicitly depicted present day unmanly Christianity in a bad light.
The storyline of Archeage is a war between whites and east Asians, and much of the game play is piracy, with much of the piracy featuring conflicts between whites and east Asians. White male avatars are depicted as way better than anyone else, even though this game was written and the art drawn by east Asians. (And, by the way, the Mongols are catboys)
All white males in Archeage are incredibly heroic and manly, and the white females are a bit on the manly side also, though with gigantic breasts. All east Asian males in Archeage have a girly appearance, and are substantially less heroic and manly. All the east Asian females have an extremely girly appearance and behavior. (You will probably want to play white if you want a cool avatar, and play east Asian if you want to look at the hottest chicks, unless of course you especially like truly colossal breasts, in which case the white chicks are hotter.) If you were to ignore the breasts (which is impossible) the white females would be about as female in appearance as the east Asian males, though white female NPCs are considerably braver and more warlike than east Asian NPCs.
Naturally each journalist sought to be holier than each of the others, thus each sought to deride, despise, and denigrate his audience more than each of the others.
This caused loss of audience, whereupon the game companies started applying large amounts of money to channels that the gamers had created to talk to each other, the money bypassing the journalists as the audience already had.
This caused a truly apocalyptic outpouring of hatred by the journalists against their audience. Or, as they depict it, an outpouring of hatred by their audience.
And that apocalyptic outpouring of hatred by journalists against those who pay their bills, is gamergate.
They always hated their audience. But it was only when the game companies started making payouts to non journalistic channels that they went raving mad.