I wonder how important the ritualistic effects end up being. If you get in trouble, for presumably large classes of trouble, you face detention. That's better than suspension or expulsion or something else that could have far-reaching impact. That people then actually show up for detention is also quite remarkable, especially if the threat of missing it or not doing the numbers is just...more detention. The waste of time reinforces the idea of "doing the time" for your crime, afterwards things are square again, like a ritual cleansing. It lets you know you can make mistakes bad enough to get detention, repeatedly even, but you can still come out of it ok in the end.

Don't understand the shorts thing in winter though.