It's a very male dominated sphere, the comedy arena anyway. When I've been to comedy clubs and they've had multiple acts I've never seen a woman even appear, so proportionally out of the women available to audiences to hear the chances of remembering a funny one is all the more harder. I think there are some good ones out there, I've heard a good few occasionally on the radio, never caught their names mind.
Also I confess, I don't mind the daftness of Millican et al on the radio 4 comedy shows, they're usually amusing enough, but in terms of stand up itself, I think we'll see more coming through in the next generation or so, but still definitely quite a cock-heavy arena.