What ever happened to kindness and courtesy?

Recently, it has become more and more evident that we have become a culture of assholes.
The most popular television shows have people screaming at each other and waving their fingers in others faces. Some are famous chefs who go into other restaurants and scream at the owners about how putrid and disgusting their food is. Others are hairdressers, or people who seem to be famous simply for being famous letting their attitudes dominate their interaction with others.
Many popular news commentators say the unkindest, rudest things they can think of, and it only seems to boost their ratings.
The leading Republican candidate seems to be striving to be the biggest jerk on the planet.
Whole sections of the country are protesting the removal of a flag symbolizing racism.
A cafe-owner screams at a small child, and everyone on Facebook seems to support and encourage this behavior.
What happened to civility?
When did behaving like this become desirable?