Why does everyone care about looks so much? i mean who cares about looks. you could be the hottest guy in the world and i still wouldn’t date you because you could also be the biggest jerk in the world!
People are shallow because society teaches them to be shallow. The media constantly makes girls feel bad about themselves by telling them that they need make-up and a bunch of other unnecessary skin products to make them look "better," same as how it constantly tells guys that they need to work out and gain a ton of muscle in order to attract girls. We're also constantly pressured to lose weight (and not in a healthy way), and with all the plastic surgery available, to "fix" the parts of ourselves that we don't like. All of these things implant insecurities into people, and then people project those insecurities by making other people feel bad.
It's part of animal instinct. The male peacock, Lions, and pretty much every other animal uses good looks to show that they are healthy and living the right kind of life for a mate to chose them. I will admit that people take this to far, but that is the deep reason for our infatuation.