In a fully private medical system people would bear the consequences of failure to invest wisely in medical goods and services (i.e. prevent worse health problems with cheap early treatment.) There would be the strongest incentives possible (your own wallet, not society's) for making the right decision. Sounds fine to me.
When you go to the ER without insurance, you get patched up and kicked out ASAP. This creates other complications... People can't work, they seek out social services, etc. So you have a situation where a chronic condition that you could manage for $4,000 a year costs exponentially more when you price in food stamps, disability payments, temporary assistance payments and other programs.
