I don't see that article blaming gamergaters for the harasser.
now that i re-read it they dont say that exactly, but here's an example:
"Yet at the same time, some Gamergaters have used Twitter to facilitate a culture of fear, where speaking out against the hashtag or even just drawing their attention can lead to a flood of unwanted attention and notifications. For anyone in gaming who uses Twitter to network, promote their work, and interact with friends, it can be exhausting and demoralizing to find oneself on the receiving end of what has become Twitter's Eye of Sauron."
same bullstuff kotaku as usual, can't even be grateful like damn