Constiutionally speaking, driving is considered a privilage, not a right. That's why it is legal for "sobriety checks", etc.
As far as helmets? It's really no different than seatbelt laws. No doubt, I think the insurance companies had alot of push here. But, I also feel the government has a role in determing what's in the best interest of the community as a whole. In reality, it not only protects the rider, but it also (or at least further protects) someone like myself from liabilty after the death of a rider I have been in an accident with.
Monetary considerations aside...if I ever did kill someone, I'd probably be an emotional basketcase. I'm sure I'd be in therapy for years!!!