"... one should pay for services one doesn't need: it's called citizenship ..."   Erhm, actually I'm pretty sure a lot of people would regard this as "exploitation" - sitting still for which definitely is *not* a basic requirement for citizenship in any just society.  :-/

It seems you are trying to appeal to a "greater good for the greater number" argument; do I understand you correctly?   Unfortunately, you make a total hash of it.  

The problem is, with healthcare there are too many ways (through addiction, ignorance, or foolish impulse) that you or I can destroy our own health, that have *nothing* to do with the general good - only with our own personal choices.  In such cases, it is then entirely unfair to suddenly claim we get to 'have it both ways' and foist the cost of our individual stupidity onto our blameless neighbors.