Walk into your local comedy club, you'll see the audience has more men in it than women. Look at the roster, you'll notice more men on it than women.

It's not that people are sexist, it's that the odds favor those who put more effort into making it their career. For every famous male comedian there's thousands who worked the club circuit for years and never got famous. The reason why more females are becoming famous in their fields is because there's actually more females entering these fields. Some are actually trying to compete against men and work hard for it.

Women can be funny. So can the guy at the local comedy club who'll never be famous because he does a set only a few times a year and he doesn't try and spread them around.