What makes you think people haven't attacked the film/TV industry, the music industry, or various religious groups as being misogynist? I've seen all three being accused. If you haven't, well, you must follow gaming news a lot more than other news. Nothing wrong with that, but you're making statements out of ignorance.
Sarkeesian has chosen to attack what she sees as misogyny in video games, much as others have attacked it in various other art forms and religions and other sorts of groups. She's specializing, which is a reasonable thing to do. She herself doesn't need to concentrate on misogyny everywhere, particularly when many other people are attacking perceived misogyny all over.
Corporate policies? You think corporate policies on women haven't been attacked? Do you read Slashdot articles that aren't about games? Have you missed all the articles on allegations of sexism and misogynist behavior in the tech industry? They attracted a lot of comments. Gamers aren't being singled out in any way, shape, or form here.