Wow, interesting thread. I'm not a sociologist but a clinical psychologist in training. So I can add my 2 bits from a "professional" standpoint, but I'd rather just voice my opinion in general 
I'm one of the approximately 1/3 of "gen X" (I just turned 30) who has decided not to have children. Many people who are either in the other 2/3's or other generations attribute this to me being "selfish." Now I may change my mind at some point in my 30's, but right now I highly doubt it. My clock isn't ticking. Anyway, is it being selfish? Maybe a little. I like my lifestyle, which includes traveling, working, going to school, hanging out with my friends, and basically not being "tied down." I enjoy children immensely when they're not mine. 
But I have to agree with the statements about kids being raised on xbox verus bikes. Grant it, I had a TV in my room when I was a kid and grew up on "sesame street" etc. But we were really active kids. There were no such things as "play dates" or the like. We all got together in the neighborhood and ran our a**es off til it got dark. Gotta be home when the street lights come on
I grew up in the suburbs of Chicago, so it wasn't a bad area. There were still abductions, I'd guess as many as there are now. But as has been said, it wasn't all over the news as much and we didn't have "amber alerts" or the like.
I don't know if you watch the Simpsons but there's an episode when Krusty the Clown's show gets really boring so the kids all go outside to play. When they step out they have to rub their eyes and adjust to the sunshine. Unfortunately that's a very accurate social commentary, and I think it's getting worse. With the pervasive fear-mongering going on via the media, I can understand why some parents would be worried about their kids safety. So instead we're raising a generation of overweight kids with really good hand-eye coordination.
I'm sort of all over the place in this post, but I think I want to mention the story I saw recently on the news that Americans are getting more accepting of being "fat" because so many are overweight/obese. That floored me, even if I understand it psychologically. Why fight the inevitable right? Yet we pump billions of dollars into the "fad diet" market, and billions more into the healthcare system to treat adult onset diabetes, heart disease, and other "lifestyle" illness. It's sad.
If I do have kids, I plan on having them ride a bicycle out of my womb.
"Only the meek get pinched, the bold survive"