First, let's define who we're talking about without health care:
The lower middle class, and entrepreneurs. The poor have insurance through medicaid. The vast majority have coverage through work. Self employed people sometimes choose to go without, and the people just above the poverty line are often stuck without insurance. But even for them it's a choice.
If you have no insurance, and you get cancer, you'll go bankrupt. But then you'll have coverage. It sucks for those people it happens to. I think our safety net could use some tweaking, it's not a perfect system. But america wasn't founded as a place for people to go to have all their needs taken care of. It was founded on the idea that we should be free to succeed or fail based on our own abilities. You can choose to spend your money on cable tv, or you can choose to spend it on major medical coverage. Because that's what major medical costs, about $50 a month (assuming no pre-existing conditions).