@Ogitoc groe sum,
People love what they percieve as good for themselves and dislike what they percieve as being bad for them.
Being beautiful, strong, intelligent, healthy, rich are all good things, so it stands to reason that people will want to be in that group, instead of the other group of being ugly, weak, stupid, unhealthy, poor, or even in the middle group being mediocre.
Add to this human beings incredible ability to lie to themlseves and live in a delusional state, you have your answer.