From my male perspective:
Theory #1: RPG's aren't marketted towards women. In my opinion, this has both some truth and some error. Truth, in that game companies rarely seem to think 'What would women like in a game' and when they do, the results tend to be stuff like 'My Little Pony' games - Which, as far as I know, is of little interest to adult women.
It also has falsehood, because what you should really be thinking is first 'What would make an interesting game for me' and second 'What would my playerbase like' - Without reference to gender. First because if you don't like it, it's unlikely anyone else will. Second, because if you just poll your player base, you'll recieve a clear picture of what they want. Then, just pay attention to the opinions presented and why.
Theory #2: There aren't many female RPG'ers. This is both true and false. True, in that as far as I can tell, most gaming groups contain more males. False, in that there are female RPG designers. They obviously have opinions and influence.
And another problem - 'Male RPG's and Female RPG's'. No such thing. I have a female friend who loves sports. She played baseball when three months pregnant, and, according to my fuzzy memory, hit a home run. I, on the other hand, view sports as a pointless waste of energy, precious brain cells (In the case of football) and bodily integrity.
On the other hand, I have a perilous addiction to high hills and biking, so there you go.
Point #1: There are some truely horrific stories of how certain gaming groups have treated female players. One gaming group had their characters consistantly rape the lone female character, played by the long female in the group. This was posted by a gamer, on a gamer site, a few years ago. Specifically, this one:
http://www.geocities.com/poetess47/gamerchick.html
If there's a point in here, it's that the question is both simple and comples. Simple, in that we need to worry more about making and playing good RPG's and less about whether those RPG's are male or female and in that we need to realise that, while gaming is a good thing, not all gamers are good gamers - And take a good hard look at how that affects our hobby. It's not enough to assume that every accusation is false; while most of them are hysteria, I have heard some truely horrid stories on our own gaming sites - Specifically, RPGnet has a thread for them that, last I saw, was dozens of *Pages* long. Granted, that was probably about a decade of experience per poster, spread over years of posting and dozens of posters, but still...
Strange that I'm so philisophical after a double tooth extraction...