Some people are mean because they’re low-class, unimaginative sadists. Maybe that describes most mean people — but set them aside, because we don’t listen to them.
There’s another type, though, that is mean because they care deeply about something. They’re judgmental because they care about something important and good. They’re critical because the thing they’re criticizing needs criticizing, for the good of whatever-it-is. (“Whatever-it-is” is something you can’t argue with — in fact, you probably agree.)
The Church Lady is the way she is because evil is, in fact, running rampant in the world. Our young people are being harmed, and the future of civilization (and our immortal souls) is at stake.
Mean Mr. Mustard can’t believe all the waste in the world. He saw his best friends killed on the battlefield. He sees the destruction our dependence on energy causes; he sees the destruction of our climate; he sees the horror of war, of fighting over resources — now he shaves in the dark and tries to save paper. He knows loss.
The Church Lady and Mean Mr. Mustard are total jerks.
But can’t you sort-of identify with at least one of them? There are real, good, important things you care about too.