Steve,
I think radio Dave's main point is; Most of the core track workers do ICSCC events ALSO do SCCA and SOVREN. Don't you ever wonder why on some weekends ICSCC events seem to be short of workers? Like corners with only one flagger or maybe two instead of three? That's because the 'worker crew' have divided up based upon their individual preferences to support a particular club.
With just a little bit of thought and working together, it might be possible to avoid Stewards walking through the paddock trying to find car crews to go out on track. Nothing like a solid staff of untrained workers to make an on track situation 'safer'
It may still be okay today. But the day will come when there just won't be enough people and a race weekend will be canceled on Saturday morning. The attitude of to heck with the workers, do the schedule and they will come won't last long unless you have a whole lotta people waiting to join the workers staff in 2014?