[Ravager]

Well, I'd say it was one way of getting people to have healthier habits before a treatment, but at what cost?
Aren't there medical oaths that a patient is to be helped in any case if possible?
Also there is no guarantee that a patient couldn't just recur into those unhealthy habits that may have caused a condition in the first place.

In such cases I believe there if a condition could be improved by stopping an unhealthy habit then the patient should be informed and encouraged to stop that habit, but not to the effect of witholding a treatment which could be potentially fatal to the patient.

Of course, to play devil's advocate, if patients who are serious about recovering are treated over those who aren't that may encourage a better general attitude among patients.