What are the cons for corprul punishment?

If it's simply used as punishment - that is, for revenge or to relieve frustrations in the person inflicting the punishment, it makes the punisher feel temporarily better. However, it brutalizes and desensitizes the person doing the punishment and causes anger and resentment in the person punished, which will cause later problems all round. If the intention is to stop the person receiving corporal punishment from misbehaving again, it doesn't work. For example, you might hear a parent say of a child, 'I keep smacking, but it does no good,' If you keep hitting another person and they still repeat the behaviour you want to discourage, clearly it isn't working, is it?