I don't see whats so bad about starting to like someone just for their looks. If your personality is shitty then the relationship won't last anyway. It's just a first impression and looks is what you see first.
My best friend is BEAUTIFUL and guys are crazy for her. Back in the day when she was still insecure (as a teen) and after getting with her the guys lost interest pretty quickly (unfortunately she was so insecure that she lost her personality when in a relationship).
Also I think all of us had crushes on people that were totally not our type looks-wise. Attraction is much more complex than just good looks/good personality.
I once had a crush on a guy who was frankly unattractive (everyone else thought so as well) and he was also very strange and awkward. But something about him was just too cute to not like.
I'm 28 btw and I never appreaciated pretty guys/girls more than I do now - I simply love to look at and admire them. Maybe I don't mind it because I don't compare myself anymore. I'm attractive in my own way and people will either like me or not. I don't have to, or rather I don't even want to, be attractive to everyone