I read all the posts and it occurs to me that this May be a generational difference as well as a geographical one.
When I was a kid (little) 50's and 60's Lady Bird Johnson was first Lady and Her Beautify America Campaign was the beginning of our environmental movement. Litter had become a big problem and we all grew up watching Iron Eyes Cody cry over the trashing of our country. That was a tremendously effective ad campaign.
Then Came High school and the first Earth Day.
The point is we grew up in a time of early and heightened awareness of littering and concern for the environment.
Now we have a generation or two that has grown up with an almost litter-free country and they may not realize all the work and heartache it took to get it that way. My bet is their Mother picked up for them and they think someone is paid to do the same at the campgrounds.
I am being very general here and fully realize there are many dedicated and environmentally aware kids out there. But sadly there is a certain type of American who just has no awareness or concern for others and feels it's their God Given right to do just as they please.
On a positive note: We just hosted some friends from England and went to Arches, Canyonlands and the Grand Canyon Natl Parks. I found them all to be spotless, litter free and my friends commented regularly on how amazingly CLEAN and well organized they were.