I don't think that is a good analogy ... many "sicker" people have played no role in their sickness which may not be related to behavior or decisions.
A better analogy would be: Why don't mountain climbers and scuba divers[1] pay higher insurance rates ?
I sort of think that they should, however I don't have a good answer as to what happens when an injured stunt skier is broke (and broken) ... do they get no medical care ?
[1] Or whatever - you get what I mean.