My sociological theory:
BHS students are not litterbugs, but they are forgetful. The evidence.
Look at all this trash under the BHS sports tree. And the garbage can is right there. But this was a Monday morning and I believe all this trash is from the visiting teams and parents and other spectators at weekend games.
This is a typical mid-week morning scene. Notice - no trash. But there are plenty of forgotten sweatshirts, t-shirts, socks and one shoe (?).
One of the groundskeepers (checking up on weirdos taking pictures of trash) corroborated my theory and told me he has been amazed at the things students have left there. Apparently the baseball dugout is another popular place to leave items. He wouldn't tell me what the strangest item was that he ever found. Makes you wonder.