I'm kind of shocked that I've been arguing with people lately who deny this. This is moral philosophy 101:
If a fellow human being is in significant trouble, you have to help him out, even if his predicament is his own fault. If I'm walking on the shores of Lake Winnipesaukee in wintertime and I see a guy about to go out on thin ice, and I warn him, and he goes out anyway, and falls through the ice, I can't just sit back and say, "I warned you. This is your own fault," while I let him drown. I have to do everything reasonable I can to rescue him. If I don't, I'm not just a smartass, I'm a bad human being.
That's why it is right that we as a society pay taxes to have search and rescue teams risk their own lives to search for, and rescue, even the idiots who ignored foul weather warnings.
So if some idiot 23 year-old kid with an overweening sense of his own invincibility decides to "risk it" and not get insurance, then yes, we, as a society, have to help him out if he gets cancer or crashes his motorcycle. We can't just say, "Sorry, kid. It was your stupid choice, and now you're screwed."