Why does this kind of culture crop up again and again in human history?
It's a very common way for insecure people to protect their positions. A person at the top is worried about being replaced by their subordinates, so they set their subordinates against each other. That way, the subordinates spend all their time on infighting rather than trying to replace the boss. You'll see this kind of thing all the time in dictatorships, but it shows up regularly with dictatorial managers of all stripes, too. It's one more variant on the old "divide and rule" strategy.