The Wikipedia page you linked says she's a "media critic, blogger, and public speaker." It seems to me those are her credentials.
https://www.youtube.com/watch?v=uqJUxqkcnKA&list=PLBBDFEC9F5...
Watch this and tell me that you think she is making an intelligent argument about anything. And while you're at it, have a think about why the comments and votes might be disabled on those videos.
That said, I think she was "all of those things" when people contributed over 100k to her Kickstarter, which was before the Gamergate harassment started. So she was earning her keep well before she was made the "public victim," as you say.
Of course the comments are disabled for her videos. Normal YouTube comments are toxic enough. She literally got bomb threats over scheduled appearances on conference panels – do you think comments on her videos are productive? If your Twitter was filled by anonymous users threatening to rape you, and kill your parents, etc., then you'd disable comments on your videos too.
I have an issue with naming of those videos. It's great to call out people who misinterpret some labels and are harmful to others. But calling that "facts vs feminism" isn't helping. His other videos manage to call out specific things like solar highway, rather than being called "tech vs facts". Why imply that feminism is bad if you're going to talk about one specific person's idea? (that's not generally accepted)
If Anita Sarkeesian went unchecked, games like GTA would be banned by now and reclassified as rape simulators.
This attitude of blindly dismissing people's arguments or entire credentials just because you bought into an agenda, this refusal to engage in civil debate and discuss matters on their merit. I think this is one of the factors destroying democracies around the world today. Everything must be polarizing, everyone expressing views you disagree with must be shunned. Any attempts to debate established status quo must be shouted down.
https://en.wikipedia.org/wiki/Anita_Sarkeesian