I think it teaches violence in young children. I think hitting your child should only happen when absolutely necessary. My older sister used to be abused by my father over eating ketchup and eggs. That, is unnecessary. My younger step brother who is very likely autistic got beat for not eating his chicken nuggets. So, like I said, I think hitting your child is mainly wrong, unless it's absolutely necessary.
Of course this is only my opinion. I was abused too as a child so I know how it feels.