Its a a vicious cycle. This behavior was learned at some point because they weren’t born behaving this way....and now it will be passed on to their children....and on and on.
Babies are born selfish, demanding, and irrational. If they are ever to progress beyond that state, they must be taught to do so.
Some people are brought up right and trained to do better.
Some people are not brought up at all.
and then ...
Some people are brought up wrong and trained to do worse.