i understand your point rainman
however assuming they want the 5% regardless of ownership would assume these guys try to win every race they drive in, given the comments i see on this site many would strongly disagree this is the case
also drivers owning horses may work opposite to your theory, since they own the horse they may actually race less aggressive some nights not wanting to hurt the horse( their investment)
either way i just think it is unnecessary and problematic
as for amateur races, they should be non wagering and certainly not held at the big m, however if people are wagering on them than they will continue
If you draw 7 & 8 on a 1/2 mile Track and 8 & 9 on a 5/8 mile Track, chances are the drive will be less aggressive. As an owner, I hope for a check in this scenario, and I say thank you if it happens! Tough to bet outside posts too. If there is no interest on the tote board, you have to assume a less aggressive drive!
Look at the money they bet on amateur races! In some cases, more than regular races! More value as a bettor but more unpredictable because of the drivers involved!