Obviously, this is a broad oversimplification, but I do think the way we manage our kids time and limit their freedom is problematic.
That said, I think many of the problems stem from good intentions and unintended consequences. For example:
1. We don't want our kids to get hit by a car, so we tell them only to play in the back yard. 2. In many homes, both parents want a fulfilling career, so most kids are in some kind of child-care after school, so our kids don't have others to play with in the neighbourood.