You know you opened up a can of worms with this question, right? Guys can be bitchy too, don't believe me? Come work with my boss for a while, his mood changes more than the sky has clouds. And when he is bitchy, he is way past anything I can produce.
Also, on a side note, women are allowed to be bitchy more often if we are good looking. Men will look past it just to have us on thier arm. It's a learned behavior. Now if you are ugly and bitchy, good luck to you honey.
--- The media doesn't help either. All the reality TV shows, all those women who throw hissy fits and THEN get what they want.