Hot chicks hate being bored. They would much rather be out at a wild party with a douche than listen to a monologue about the attenuation characteristics of monster cable.
Being with a douche will have good and bad times, but most of the time it is not boring. Many hot chicks don't have a very high self-esteem or many real accomplishments to speak of and they know that their looks are mainly what they have going for them, and often they are not very secure about their looks either, so they get to feel special when they get to think that they are the only one who can bring out the "sensitive side" of an
a-hole. Also, a-holes have many more opportunities than "nice guys" to demonstrate behavior that the female mind interprets as confidence. Human female minds are no different than any other animal, their brains are "hard-wired" to mate with alpha males.