In speculation the two issues would be first, there would be no need to sign up early. Didn't I see at east one round this year being cancelled due to lack of participation? If they don't see any pre-entries then why bother hold the round? Would you as the race promoter dish out the $16K for the two days only to take the hit with no participation?
Secondly, I can just see more of the folks trying to get a better starting grid and running harder in practice to accomplish this. could this relate to more crashes because racers are attempting to go faster by pushing the limits a little harder? Just saying.
Mark