In 2010 giving a lecture to students at a college she says
"I'm not a fan of video games, I actually had to learn a lot about video games in the process of making this"
Why does it matter?
She has claimed time and time again In the media that she's been a life long fan, and that has been the motivation behind her campaign. Yet as we can see, its not true.
Furthermore she later on dismisses all shooting games as "gross" in a stereotypically "girly" way, which just doesn't fit with her current "I'm a gamer girl" act.
This has nothing to do with the points made in her video, that's another discussion all together, but whether or not her motivations were honest from the get go are a valid question. She does seem to have at the very least misrepresented herself.
This also matters because she's been at the forefront of shaping the debate on this, and sadly the tactics she has used have been less than conducive to free, honest or even civil discussion.
Its clear that she decided she needed to put on the pretense of being a gamer so she could tar all those who would be against her from within the group. It makes for a better narrative than a feminist "pop culture critic" commentator going after video games from outside fandom or experience. I guess it was just another measure to help insulate herself from criticism.