Pretty simple to me. Either join your club team and compete or join your middle school and compete. If your prodigy is too good to work with some middle school noobs and help them get better, then get far away from the program. One of the best ways for middle schoolers who have never been a part of the world's greatest sport to improve is to have them watch teammates who have some experience properly warm-up and control a match. Don't do both and encourage your child to break the rules in the process.

..and is it the kids that are electing not to support their middle schools or is it the parents? If it's the kids, then I would say you are giving your 12 year old one hell of a say in how your run your household.