See, now I disagree (big surprise, I know).
People do all kinds of things that are unhealthy. I would venture to say that the overwhelming majority of people in America engage in unhealthy activities. So, clearly, there is plenty of precedent for doing things that are not in your own best interest from a health standpoint. If someone wants to kill themselves by engaging in unhealthy activities - whether its diving with bug problems, smoking, race car driving, competitive crack smoking or anything else, I say more power to them. However, they shouldn't drag other people down with them. So, referencing the case above - if you end up with COPD, you should not necessarily stop diving - but you should stop diving on charters and with a buddy - reducing the the need for anyone else to have any liability or need to rescue you. That's only fair and reasonable. Be a solo diver - go have a good time.
I suppose one could make the argument of, "but you would be putting at risk those who have to go get your body out of the water" - but I would argue that such people signed up for and are often paid for doing just that, so they have no room to complain about it being unfair or unreasonable in any way.