It's star quality. We see them on celluloid and in print and it gives them a mystique and charisma that 'normal' people don't have.
You go to any club on a Friday night and you'll see women that look just as good, if not better, in terms of physical features. However, they are not deified and worshipped in the way that famous people are. Fame and wealth are bigger factors than looks alone and it's practically irresistible when all three are combined.