Why is it important though? I don't really care if some dude in wherever plays as a male toon or a female toon. The numbers does not reflect reality of the gender of the gamers since not everyone is playing their own gender.
Also set gender games are worse than char gen games imo but that is because I prefer my own characters but I think that it should be up to the developers to do what mian character they want and not care about what others think since the sales numbers will represent if they did a good or a bad job.
I want people to play who they want to play. My interest in the number is that a higher female character percentage in games like these might open those options in other games in the future. For instance, I would've loved to play as a woman in The Witcher or Deus Ex worlds. Though I know that those are set characters and that's fine, but if a higher percentage of people played female characters, maybe they would've at least considered the option during development? (Probably not those particular games but still)
A lot of game companies aren't interested in publishing a game with a female lead because they believe it won't sell well. I simply wish that weren't the case.
There was an article about a game on The Escapist website that had female leads and no one wanted to publish it unless they changed them to men. Doing so would've changed the whole dynamic of the story and it would've been completely not what the developers wanted to do.
Most important is the character the dev's feel is the best for the role. Always - I'm not saying they're not, If a male characters who they have in mind I've no objection. I've played countless games with male leads and they were great leads I'm just talking about games that wants the player to make choices and shape a world to have the option to include a gender option as well. Plus, I never said that only woman play woman and men play men in games as that's completely false and untrue.