Same reason why the 'ugly' girls never get boyfriends in high school.There's exceptions to both situations of course. But I think its a maturity thing, where they just like the way a person looks so they want to be with them, without thinking about how big of a douche they are. A lot of girls (like me) could care less on how a guy looks. Its just a maturity thing. It comes with time.
Some girls expect that, but most of us realize that guys (and girls) are not perfect. In fact, if I had a boyfriend, I wouldn't want him to be perfect, because I realize I have faults and I'd constantly be reminding myself of how unworthy I was of him in all his perfection. Don't stress, give it time, and be open. Everything'll be good :)
I'm not going to go out with a girl that I don't find attractive at all so I would expect the same from her. Now ask yourself do you care about looks? If you do care about looks than obviously you shouldn't expect girls not to care about them.
Well, girls who lack a certain aesthetic appeal aren't superficial, they can't be. Because all the attractive guys are superficial too, and they're only interested in girls who are a little easier on the eyes. If you want a more attractive young lady, you might need to become a little more attractive yourself. Failing that, you're gonna get whoever is left, which generally isn't a desirable option.