It's a simple explanation. With both parents working, there's less time to prepare healthy meals, junk food is cheaper than ever, and nobody lets their kids play outside anymore. The parents all say they're scared of sex offenders despite the fact that statistically it's safer than ever.
I'll kick my two boys, 6 and 8, outside every chance I get. I tell them to go ride their bikes, stick together, and don't come back until it's dark. They often have a hard time finding other kids to play with. Most of the children in the neighborhood their ages have structured free time under the watchful eyes of their parents who won't let them venture past the front yard.
Good for you. But the way things are nowadays don't be surprised in Child Protective Services or whatever shows up to counsel you about your free-range children.