@th3j35t3r The logical extension of that is the "individual pool": each person negotiates a level of coverage and premium that gives acceptable care at an acceptable cost, with the insurance carrier making only a reasonable profit.
For the average male in his late teens, the coverage would be good and cheap, because those guys are almost indestructible. For the same guy in his 70s, not so good and not cheap at all, but what the hell he ain't got that long anyway.
TL;Dr: bloody stupid idea.