I agree that the behavior of kids at WDW has deteoriated since I started going back in the early seventies. But it is not just the kids. It is the bahavior of the adults as well....People going to nice resturants in EPCOT wearing a tank top. People pushing and shoving, running red lights, littering. The fact is that there has been a great dimunition in politeness and good behavior in our society on a much more general level than limited to WDW.
As to the blame the parents crowd, this is clearly part of the problem in some cases. But our children spend a great deal of time in the outside world, where parents don't get to control what they do and see. I have two eleven year old twins, and they are among the only children in their class who do not have cell phones and watch South Park and Family Guy. I like those shows, and I watch them, but don't allow my children to. They go to a friends house and the parents have Tivoed the programs for their children to show to mine without my permission, after they have played the latest ultra violent video game (another thing my kids aren't allowed to do). It has been said that it takes a village to raise a child, and even though Hillary was the one to popularize the saying, it is true. Every time my child sees you blow through a red light, or answer a cell phone during a movie, you are teaching them that disobeying the rules is acceptable behavior, just as I am trying to teach them different. A lowering of politeness, abidance of law, intellectual persuits, and good taste are the earmarks of a society in decline. Look at the the history of defunct cultures. This seems to be where our country is headed, at WDW and elsewhere.