Because they're stupid.
Stupid enough to key somebody's truck ...
Back during the election, I was walking into a grocery store and walked past a car with a bunch of off the wall anti-Trump stuff on the back window.
Did I key the car? Nope...did I even THINK about keying the car? Nope....
I just walked past it laughing and shaking my head. I know, crazy right?
I swear these people are mentally ill. THAT is what liberalism does to your brain.