I don't understand...

Why does my school not allow kids inside after hours? I know that there is a possibility of vandalism and kids need to be supervised, but what if there waiting for a ride to come? I would rather wait somewhere warm than outside in the cold. Some kids have a b-ball game after school. The game doesn't start till 5:45, but they start changing at about 5:00. If school ends at 3:30, most kids can't get home, eat, and get back in time. Not everybody lives within walking distance, and bus rides can take up to 1.5 hours to get home. Even if they do get home with enough time, do they have a ride back it?
I say let the kids with after school activities stay if they want, but in a controlled area. Don't let them have access to everywhere in the school, but just in the gym, outside the gym, or in the locker room. I think that it would work well for the school.