I always thought vampires preferred beautiful young men and women, and so they would go out of their way to drink their blood. Then the prettyboys and prettygirls turn into vampires. Simple as that. Super model vampires make perfect sense to me.
HOWEVER; I think that vampires should have an ugly side that comes through when they're angry, hence Dracula's transformation.
Anyway, it doesn't matter. I can totally see myself whipping that ugly vampires arse.