Social norms change. Samurai used to ride around and slice people in half just because they could. Public hangings and lynchings used to happen all the time. Most places in the world have eradicated that sort of murder out in the open, and the ones that haven't are making concerted efforts to stop it.

There's nothing about human culture that's consistent except its inconsistency and adaptability. It might not be obvious within a few decades, but big changes do happen.