There's a lot of factors at play here.
For one thing, apparently you can't discipline your kids anymore in this day and age, because it's considered "child abuse," and you can get locked up for it. As I said, back in my day, a spanking was something you might get if you're in real, deep trouble, but as the years went on, more and more people argued that spanking or any other physical punishment was child abuse, so you'd be hard-pressed to see kids be met with a belt for acting up.
Another thing is that we kind of live in a time now where kids are almost always forced to grow up too quickly and not even really get much of a childhood, and I think it's because you can't really reason with kids like you can adults, and people don't have the patience to want to deal with kids, so try to mold them into mini-adults as quickly as possible.
But one of the biggest problems too is that too many parents as still kids themselves: kids today aren't properly educated about the facts of life and what have you, so when their hormones get to raging and they do regretable things as a result and end up having babies, they're not prepared to raise these little bundles of joy, and those babies end up growing up messed up kids because their parents don't even know what to do with them.