Appears to me almost everyone is missing the point. The rules really have nothing to do with children playing. The rules have every thing to do with behaving in a sociable way.
Think how you should be have at a family restaurant vs how you should behave at a biker bar. If someone is so daft as to think any behavior should be tolerated in any situation and if it is not, it is PC, then you truly are beyond any hope of understanding normal social standards.
HiTech