The issue, I sincerely believe, is a form of justice that goes beyond "eye for an eye". I call it "face for an eye": a beatdown in response to a sucker punch.
The cause, frankly, comes from severe psychological trauma that breaks sensible thinking [1]. But, it's no excuse.
The solution? I believe it requires making people more moral, thus making them more just. How to do that is, effectively, something I believe is beyond the scope of my understanding.