Bryan Caplan explains the difference in perceptions between health care insurance and auto and life insurance.
I agree that there is a popular perception that health insurance is an unusually crooked industry. My main explanation is that customers of health insurance companies have more latitude for unreasonable demands. If your dad dies, the life insurance company owes you $X. If customers ask for $X+1, the firm refuses, and no one sees this as proof that the free market can't be trusted with life insurance. If you get sick, in contrast, it's hard for an insurance company to decisively prove that they've lived up to their agreement. You can always insist on another expensive test, even if the insurer knows it's useless.