I hear your point HH. I grew up with minimal corporal punishment and learned fast to listen to my parents. However, not all kids have the ability to reason in the way you and I did, therefore, hitting can bring out a worse behaviour in certain children. They learn to hit others to get their message across.
It is sad that the parents do not take a united front with teachers (I always did), but I also know that there are some teachers that should not be teaching any children. They are burned out and have no patience for the differences in children.
It is definitely a different society today.