Hockey is a contact sport, so there is nothing wrong about playing physically. The whole idea is for kids to have fun. The Ontario Hockey Federation defends its move by saying kids at the ages of 12 and 13 are suffering injuries from bodychecking. Better to teach them at an early age how to handle contact. That's a fact at any age.
Nobody can refute that.
The issue of bodychecking isn't the real problem. From what I'm seeing, we're not developing skills. Some parents do favour contact for children starting at eight years old. When the head of a hockey association in Ontario heard that the OHF was lowering the age for bodychecking, he was delighted. The element of fear may work for an unskilled player trying to impress a coach, but it inhibits smaller children with ability from developing.