If a pet rock was installed as CEO instead of Mayer Yahoo would be a more valuable company today. She didn't ruin it, but she sure helped shove it off the cliff.
Mayer's performance had nothing to do with her gender. I'm adding this statement to respond to some other peoples' comments.
I also wholly agree that diversity for diversity's sake is idiotic. Can't wait to read The Verge and Ars Technica spins on this one..