If it was once a year, I would agree. I think you would have people who are not running up front now, Bailing and stepping down. Look at how many names in the 305's came from 410. I first went to Shady Hill when Warsaw closed. Open wheel has never really caught on there. Same with Montpelier, when they tried to run sprints weekly.
I don't see 30 to 40 people saying, if someone started a crate series, I would buy a car and go racing. The teams would for the most part, already be participating somewhere else. Eventually, races draw less fans and pay less money. The promoter then has to load up the back gate to try to break even