I think that retribution leading to more retribution probably caused rulers to step in. A disorderly society is dangerous for the ruling class. And that was more selfishness than concern for people: the ruling class wouldn't care a bit about the death of a serf unless it affected them.

You see vestiges of that today. A gangland shooting doesn't get the attention of a gang war. A hurricane that destroys your house is your problem, but hundreds of houses affects business, so government aid is given.