Guests are pigs. Whether they are worse here in the good, old USA is debatable. Europeans are as bad or worse then Americans. Asians, by and large, are much better and more respectful of rules and private property.
While HKDL was near pristine, DLP constantly has to deal with guests who openly are ... well, pigs. The queue for Peter Pan (which I will put a picture up if I ever have time to write a Paris/Anaheim observation thread) was absolutely disgusting last month. Imagine the men's room at a truck stop ... just covered in graffiti all over. A few years ago, BTMRR was like that there and they had to rip out all the wood in the queue and replace it.
PP was the only queue with those type of issues, although there were a few tags in Thunder again and I openly saw some loser trying to scratch something in a railing of ToT's outside queue.
Back to WDW ... TSMM has been a disaster since it opened due to the cheap materials used and guests ability to rip chunks of walls off. It is very similar to Buzz at MK.
In all the cases above, whose fault is it?
Disney's of course.
Guests are pigs. Fine. They have always been to some extent. And guess what? It doesn't matter. It's Disney's job to clean up from them -- no matter what.
It's the very basics of theme park ops. Walt knew it.
One piece of graffiti or trash in a queue is a problem because the sight of it allows other weak-minded losers to think it's also OK to trash the place. One leads to two leads to eight leads ... one helluva mess and bad show.
It really is simple.
You can't make people less boorish by leaving the bad behavior of others for all to see.
You get rid of it.
A pristine queue is a lot more likely to stay that way.
No excuses for TDO.