Why Aren't People Nice?

Today a random stranger on Facebook posted the comment that Robert F. Kennedy Jr. should "do something about" his voice, because it's "really annoying." Was he suggesting that Kennedy cure himself of spasmodic dysphonia, which causes the muscles in his larynx to go into spasm? 

Because I think we can all agree that Kennedy would prefer being able to speak normally. He has even said he can't listen to himself! Still, he's got the guts to go out and seek public office despite his condition, which is admirable in itself.

People are so mean to one another, and especially to strangers they have never met and know nothing about. It's so disheartening, and has so little in common with the lies we feed our kids in childhood. We tell them to play nice with everyone, but then they grow up and see that nobody plays nice. Thus, alcoholism, drug addiction, obesity, depression and suicide run rampant.