I ran my own small business, provided great healthcare for myself and a couple of employees, and managed to have good healthcare after I shut the company down and was unemployed for a while. I had to do a little research and make a couple good decisions, then it wasn't an issue. And that was before the Affordable Care Act, which provides free healthcare in many states for people who can't afford it.
The one thing is, if you are not working for a decent company, yes, you have to think about it and prepare for it before hand, it isn't all taken care for you without you doing anything. So I say, for the vast majority of people on HN it's not that bad.
And worst comes to worst, you are being irresponsible or have fallen through the cracks, and you get into a car accident, the hospital is going to take care of you anyway.