Im not sure how it is in Australia, but here we pay our tax for smoking. Its included in every cigarette pack cost, and many of us, smokers, never even use the social health-care so we kind of pay for all of you no smokers as well.
I don't see any reason why smokers should be denied the right for medicare, we pay our dues to it, and the more we smoke the more we pay for it.
And i don't like such ideas in general. It starts with smokers, and then what? People who casually drink alcohol? It can lead to health issues as well after all. Then we will move step forward and refuse to treat everyone who has some predispositions to get ill?