Pretty sure this is a Freemason thing.

When you fuck up, you get whacked in the eye publicly with a wooden mallet. Then you have to carry the black eye around so everyone else in the kid fucking club knows that you were punished. It’s a way of demonstrating no one person is ever more powerful than the organization. You can get hit like a bitch even if you control an army and nuclear weapons.

It’s basically the same reason they have them all the pedos. A way to control powerful people.