I have a theory that it has something to do with the whole wave of "spanking is not the answer" discipline approach.
Personally, I don't know how you feel about spanking, but I was definitely spanked. I was not one of those kids who could mouth off or act a fool.
My mom says It became at one point that, if parent physically acted upon a child in such a manner, all the child would have to do is call the police and say "Hey, my mom/dad beat the crap outta me." and then get the parent in trouble.
Here's a site I found with different law pertaining to spanking.
Spanking Laws
That's why kids TODAY are different from yesterday. The parent is scared to discipline them in this fashion, so the child/teen runs a amok knowing that they can call the police and get the parents in trouble.
I agree with you, I think I act much better than majority of kids today, even when I was younger (I'm 18 now), but also, I've always been quite mature due to the fact that I was never really treated like a child; my parents never talked to me like a child. Also, by nature, I've never been one to act out.
Being a child of spanking, I believe in it. I see children misbehaving in public or even children of friends of mine and my mom when we're hanging out privately. All the parent does majority of the time is say "Stop" or something to that effect. If that were me, my mom would spank me in front of everyone to embarrass me, which would ensure I didn't do that again. I think some kids just need to be spanked and embarrassed. Some may say that will create resentment towards the parent. I say, they're children. They need to be taught how to act before they get in public and make fools of themselves and make the parents look bad.
That's just my theory though.