I continue to hear the "roughly half of gamers are women" statistic and I continue to not believe it.
Why? Because, A) it seems to come from game distributors who have an interest in getting women to buy more games and, B) I simply don't see women playing games. I don't hear them chatting over headsets online. I don't see them at game stores. I don't run into them in bars. None of my female friends, who tend toward nerdy, game much. If there's so damned many of them, where the hell are they and what are they playing?
Sure, that is anecdotal, but I simply don't believe that women are into video games as much as men (in many ways a credit to their gender).
Game producers aren't stupid; it's big business. If there truly was a gigantic, under-served female gaming community, chomping at the bit for games with strong female characters, we'd see more of them.