Why is it not allowed/ illegal to punish/ / beat up the children when they gone worst in USA?

Because it's been found that kids who grow up to be drug addicts and prostitutes often start off as abused children. We have laws to protect children to stop that from happening. We're also very anti- human trafficking which happens a LOT in your part of the world. We have different social values. Don't judge America by what you see on TV. It's a poor reflection of us.