The assertions is that unlike auto insurance where many people go there whole live with a serious accident, everybody needs health insurance or expensive health care. This isn't true for young and middle age because a small percentage of the population consumes a huge portion of health care costs.
In the same way that average drivers would save money over their life with a high deductible and paying for fenders benders out of their own pocket. The same thing is true for most health care consumers, if we got higher wages but no insurance and then paid for medical care out of pocket (e.g. paid a few hundred for annual physical) most people would come out financial better. Obviously the unlucky person who gets a cancer or brain tumor goes broke.
I personally like to see us move to health care system, were preventative care was inexpensive, and catastrophic diseases were covered, but routine health care (Viagra, birth control, cholesterol drugs, pregnancies, broken arms) was paid out of pocket. Of course this has no chance of happening.