Because a powerful, mysterious man is sexier than a pretty boy. Pretty boys are like girls, they're always being judged by how they look. Power comes from the freedom of not being judged. Constantly being judged on superficial things is what makes women less powerful and more insecure. You feel powerful when people can't tell you that your eye shadow should be a little more blue, your tie is too patterned, stuff like that. When you look like you don't give a shit you exude confidence and power, people will shut up.