This is an interesting piece about how we, as a culture, shelter our kids far more than our parents sheltered us for no rational reason. The author suggests a few reasons like this one:

4. Collective-action problems. When it comes to safety, overprotective parents are in effect taking out a sort of regret insurance. Every community has what you might call “generally accepted child-rearing practices,” the parenting equivalent of “generally accepted accounting principles.” These principles define what is good parenting and provide a sort of mental safe harbor in the event of an accident. If you do those things and your kid gets hurt — well, you’ll still wish that you’d asked them to stay home and help bake cookies, or lingered a little longer at the drugstore, or something so that they weren’t around when the Bad Thing happened. But if you break them and your kid gets hurt, you — and a lot of other people — will feel that it happened because you were a bad parent. So you follow the GACP.

Over time, these rules get set by the most risk-averse parent in your social group, because if anything happens, you’ll wish you had acted like them. This does not mean that the kids are actually safer: Parents in most places “shelter” their kids from risk by strapping them into cars and driving them to supervised activities, which is more dangerous than almost anything those kids could have gotten up to at home.

I find myself falling victim to these social pressures from time to time. We live in a relatively safe town – probably as safe or safer than the one I grew up in. As a child, I walked and rode my bike everywhere for hours at a time away from parental supervision. It was part of growing up and if I wanted to go somewhere, I was often expected to get myself there. It taught independence, problem-solving, and responsibility.But such things are frowned upon nowadays.

So while I do make my kids walk to school (half a mile away) and to work (about a mile), and I let them walk to places like the library (about a mile and a half) or park, I do occasionally get a pang of apprehension that my neighbors/friends/fellow parents may think less of my family because of it. Fortunately, those pangs pass quickly.