Firstly, awesome website! Secondly Awesome topic!
I am a dude and have created a female protagonist [well I've MANY but only one of them has a webcomic about her for now. Franqui 'n' Friends
The reason is one that I always ponder on myself frequently.What I seem to land on the most are two things.
As I was growing up there weren't many good female characters, compared to all the rad, awesome dudes.
For me female characters are able to express themselves in a more profound way.
For me, being the late 20s male that I am, the female character is one that won't be questioned when she shows her "soft" side [affection, sorrow, etc.], the Female character is celebrated when she shows her "hard" side [tough, gritty, etc] So the female character is one that can allow for a wide range of storytelling and is more appealing/can be easier to accept.
Not to say that Male charactera can't be accepted, it just seems to me, in my head/opinion, that the female character is quite a powerful thing to have.
Well, that's my Two cents. Again GREAT topic!
-Nelson