Grate topic !
I think a feeling of being powerless creates anger. Maybe people feel there are too many other people sticking their noses in on what you can think, say and do when most of what you want to say relates to other people who are seen as getting a free ride. A daily diet of you are racist, heartless, homophobic, ageist, mean, greedy topped with you are either too fat, too skinny and a wacko for letting your kids eat certain things whilst you're also negligent for letting them eat other things.
Or maybe Moral authority used to be derived by a persons acts, think of the student standing in front of that Chinese Tank or Thatcher sending the Fleet to the Falklands. Today the ultimate moral authority is to be a victim and the bigger the victim you are, the higher your moral authority.
Indignation and anger is the currency of victimhood. No wonder these feelings are on the rise. This country badly needs its heroes back, real heroes, not heroes just because they are an offended minority.

Morality which depends upon the helplessness of a man or woman has not much to recommend it. Morality is rooted in the purity of our hearts.
-Ghandi