I think they treat them differently cus people tend to flock to other people that are similar to them. I don't like the term ugly , just sounds so hateful . But you know if someone attractive sees a similarly attractive person they kinda gravitate towards each other . It's probably to do with evolution and natural selection or something . But who cares , just make the best of what you have , I think I've called someone ugly maybe once in my life , I was young and I didn't say it to the person, but really I try not to judge looks, they don't mean much.