in Australia, NSW two of the most successful clubs have been run as not for profit organisations. My club is 30 years old, has hosted the 2001 worlds, and is still going strong (
www.moorebankraceway.com) the other club in NSW (
www.pdnracing.org.au) racing only at nights, has 80+ drivers each night (races buggies onroad, 8th scales tourers) and is also a club, not for profit.
other club's in the NSW area that have stood the test of time are clubs. There are only two private tracks, one not going so good, the other is an electric only venue and is very succesful.
Also in Australia (QLD) most club's are not for profit and going very strong. The biggest onroad club in Brendale hosted the 2006 tourer worlds...it's also a club.
You need people to run it, and you need to foster a collectivist attitude....you can't be individualistic when it comes to this hobby or, as you guys are now experiencing, you will suffer from lowered venue numbers. Pull your fingers out of it, and start teaching the young kids to help, and tell the older guys to lead by example!
it works all over the world, so there is no reason why the yanks can't do it.