Meh - I've got no love for car insurance either, but there are several key differences between health insurance and pretty much all other forms of insurance (car, homeowners/renters, life, etc.). The others all compensate you financially after the fact. Bad event X happens, they pay you Y. They reneg on the deal, you can go to court and while it might take years, you're still only out money in the interim.
If health insurance decides not to cover your chemo, you're farked more than just financially. You can still take them to court, but you'll probably die in the meantime.
There's a healthy competition between traditional insurers which has never existed among health insurers. Primarily because they areare actual insurers in the traditional sense while health insurance is almost a misnomer in this day and age. You're not paying for insurance, you're paying for coverage.
