Doctors are expected to give the proper amount of care so they do that. Doctors doesn't care about what this will eventually cost for the government. The doctors work for private companies so the have no incentive to limit the care. They also have no big incentive to provide more care than needed.
Anyone can go to a doctor to get an appropriate level of treatment. If you want more than that, to the degree that you want to waste your own money, then of course you can do that by paying for it out of your own pocket.
It's funny that we are having this discussion. This is a solved problem in large parts or the world and the only reason it's an issue in the US is due to people being crazy.
I don't think its a solved problem at all. Healthcare costs are an issue in terms of spending per capita in the whole world. And the "whole world" depends in great amounts on the pharma and medical research that is developed in the U.S., and exported for very little in return. Furthermore, countries have varying levels of care based on the countries budget.
When the rich people in europe get sick, they go to the U.S..
