I mean, we don't make it illegal for people to do a ton of extreme sports where they might die. I don't see much of a difference between, say, climbing Mount Everest and a healthy, wealthy person deciding to spend thousands of dollars on something other than health insurance, knowing that they might not be able to pay the piper. Both are instances of someone choosing current enjoyment and weighing it against the chance of a life-threatening outcome.
The real problem seems to be when people have no choice. Of course everyone wants to not die, and of course no one wants to pay for healthcare, but we can't have both, so we have to find a middle ground that involves preventing deaths and paying for healthcare, and it doesn't seem horribly immoral to me to allow people to make the choice to trade their future health for money now (or enjoyment, in the case of mountain climbing or sky diving or whatever). Once again, the problem lies in the lack of choice from the get go.