They're being a bit hyperbolic. Your post was about 70% true. The relationship between Zoe and Nathan Grayson was real, he did report on her and her game without disclosing it, which Kotaku later acknowledged, albeit over a week later. Although he didn't write an official review of her game. What caused it to blow up was Kotaku blacking out the story, despite pouncing on game dev sex scandals in the past. It's a topic that's guaranteed to generate buzz, readers just flock to it for whatever reason. Even if there ultimately was no breach of ethics, going radio silent on the most talked-about story of the day turned it into the most talked about story of the week, and gave already-paranoid idiots the false impression of a game journalism conspiracy, coverup, etc.
Again, there was no positive review written for Depression Quest, but you can't expect tens of thousands of individuals to do their own journalism to discover that. So in that short timeframe, some trolls and her already-existing detractors spammed the initial report everywhere they could, just to give it visibility. So you had a story of press corruption flowing through the underbelly of the internet, that the press wouldn't comment on, which only appeared to give it more credibility. And with the gut impression that something was amok, people started digging for any other hint of corruption they could find. Backgrounds were checked, links were drawn, conspiracies piled up, at this point it started looking more like a consumer revolt. And then something like 10 "Gamers are Dead" articles were published on the same day, which convinced the gamergate folks that they were onto something and the games media was conspiring to crush them for it, and that the random trolls in their ranks were being picked out as a desperate attempt to discredit them. Because to them, trolls were not a new thing.
This was the paranoid fantasy that was born.