Most people - even most Americans - aren't libertarian minarchists who believe everything the government does is harmful by default and that free market capitalism is an unalloyed moral good. History has shown that the kind of governance you want rarely works out well for anyone but oligarchs.
I don't believe everything the government does is harmful. Personally I'm quite fond of the FAA despite the many that complain about TSA.
But most of what the government does introduces dead weight to economic transactions or moral hazard. This is especially true when the government tries to provide social benefits beyond taking over a product or service that could perfectly well be provided by the private sector.
I would have little argument against the government regulating that private healthcare providers cannot discriminate on the basis of preexisting conditions. It would increase costs uniformly across the industry. I do have arguments for providing healthcare on the basis of income, as I believe the program would be better served by private charity. Those who argue the contrary do so only because they want to force all citizens to contribute to the private charity (run publically) of healthcare-for-the-poor, because they want to solve someone else's problem but don't want to have to bear the burden themselves.
