Rather than editing my prior post...
I'm sure some people would argue that you need the extra teams and some of the marginally talented players in order to build the sport. I understand that argument, but disagree that school soccer is the place to do so.
I would suggest working locally at the Y or wherever to build and expand the rec program and get more older kids playing there. Clubs like CESA and CASL do a great job of offering rec for older kids, as well as adult leagues.
Thats the path for growth....not extra school teams.