I think TG's problem was to quickly get a car that was inexpensive for team owners but also the series was going to focus on oval racing which presents several issues
By the end of the CART series the technology was such that speeds had reached very dangerous number. There was a collective sigh of relief when you left a track like Michigan without anyone getting seriously hurt.
Now the new series was going to be all about that type of track plus the 1-1.5 mile tracks where packing that many open wheel cars into that small a space was going to ramp up the contact.
Every major league series has struggled with the problem of slowing down fast cars, and I don't think a solution that pleases everyone has been found. TG had to quickly come up with at least a quick and dirty solution.
With that said, he destroyed open wheel racing in the US. I have come to understand some of his reasons for what he did,Roger Penske had much more blame than meets the eye, but Tony George decided to take the nuclear option
Indy car has been a sad back water series ever since.