Once upon a time, kids were part of the world. They were allowed to go places, do things, meet people. They were active.
For "active" now substitute "activities." Kids participate in activities created for them, not by them. We take them, show them, teach them, protect them in a way that most of us -- given the choice -- would have rejected in favor of adventure.
For an illustration of how childhood has changed, here's an old chestnut I love: Sesame Street's "We lost our dog" video from probably the 1970s and then the updated version. Note who is missing in the early version who shows up in the second:
Mommy (and the prop baby, there to make mommy's presence seem "natural," I suspect). She is with them every step of the way.
This is how we get the message that letting kids do anything on their own is wrong: We stop seeing it. It becomes taboo. It may even become illegal.
At Let Grow we are dedicated to hunting down childhood independence and returning it to its rightful owner.