They get a chance to get noticed and possibly go into professional sports if they do play on these teams and are good enough though and that can pay off big time in the long run. I think it would be good if they were paid a little bit for the time they put in and to compensate for injuries they might get while playing/training, etc. However the main problem with that is that before long they'd be agitating for a "living wage" from it and it would just become a giant nightmare. So I can see why they're not paid.