I don't think you even know what "alpha male" means.

http://en.wikipedia.org/wiki/Alpha_male

"In social animals, the alpha is the individual in the community whom the others follow. Where one male and one female fulfill this role, they are referred to as the alpha pair"

Girls want to be part of an alpha pair, it's as simple as that. I think you are projecting your own warped ideas about sex ("humiliation") onto this. But hey, whatever floats your boat, we're all grownups here.