Why is beauty seen as one of the most highly valued attributes in Western society? Beauty is a sign of good genetics(as if it was a mark of having good genetics). If you think you've seen a beautiful person who has proven that his/her genetics aren't good, then I would ask you, how beautiful was this person? If it's just a cute face, I wouldn't class that as beautiful. The best of the best beautiful people tend to have good immune systems, great minds and perfect bodies.
Imagine if we had to create our own beauty, such as by selecting the universe to be born into, selecting the parents, and competing against others for those selections. This would add a bit of fairness to beauty, as it would have to be earned.
There are some really beautiful people, far greater than the famous, with genetic mutations resulting in larger smiles, more symmetrical noses, carved out, 'arc'd' eyes, sharper complexion and red lips and so forth.
Beautiful people tend to have symmetrical and perfectly shaped body parts, such as perfectly shaped feet and hands. If the genes are the best of the best, everything about you is a higher quality than the rest...
People tend to prefer the more perfect bodies and minds to the lesser ones. It's in our nature to create idols and we idolize beauty because it gives us something to hope for, to hope to become in the future.