Yes, but, that is why the normal H-Pattern gearbox is much better. You actually CAN screw up and kill the transmission. The race winner should be the one making the fewest mistakes, and, busting a transmission would be a BIG mistake on the drivers part, and he should have a consequence. Also, so what if all road cars are S/DOHC? One of the best cars in the world right now, the Corvette Z06(I know that seems biased, but it isn't), has a CIH engine. Besides, if they let FI in, then that would call for a more complex computer system, with the ability to hide TCS easier. TCS=Lame.
Cheers,
Matt.