One of the biggest problems with requiring regionals, are out west where you have 14 to 20 hour drives to get to a regional race depending on where it is held.
Region 11, for instance, drivers from Billings would have to drive 16+ hours to Washington to go in a regional race. Plus whatever it would take to get to nationals later that year.d
My Region, 10, is a 12 to 18 hour drive to the big tracks that normally host regional events. My track held the Region 10 off-road electric championships in 2006. We had 1 driver from Colorado; 15 from Montana. So Arizona, Utah, New Mexico, were all unrepresented at our regionals. The rest were Wyoming drivers.
Paul