Those who make the argument, in the name of individual freedom, that those who so desire should be able to opt out of universal health care do not understand how insurance works and should hold their peace, mainly to safeguard their credibility, but also to spare others the pain of having to to sit through their ill-conceived defense of personal freedom.
For the last time, here is why letting people opt out of universal health care is an idiotic idea (there are probably other reasons why allowing people to exercise individual freedom in matters of health insurance is a bad idea, but the few listed below suffice):
If people who have a reasonable expectation not to get sick (mainly the young), or anyone who simply chooses not to participate, were free to opt out, prices would automatically go up for everybody else, because the financial exposure for insurers would rise and they would have to compensate by raising participants' premiums to the degree necessary to maintain profitability.
Also, the idea of affordable (and profitable) insurance is that risk should be spread out among the highest possible percentage of the population. In the case of health insurance, such percentage should be 100%, because no one goes through life without requiring health care services. A good and lucky driver could go through life without ever being involved in an accident. A good human being will sooner or later develop pneumonia, require surgery of some kind, and consume a significant amount of prescription drugs in his or her lifetime. If the only ones to participate are those who carry the highest risk, then insurance can legitimately request (and get) laws that allow exclusions for pre-existing conditions.
Finally, one could make the argument that anyone who chooses to opt out of the system until the time comes when they know they need to join are opportunistic, unethical leeches, rather than the champions of individual choice they are made out to be, and anyone who makes an argument in their defense is either stupid, intellectually dishonest, or an opportunistic leech him or herself.