Yes, there are those who smoke and are fortunate enough not to fall seriously ill. However, this does not prove that smoking does not damage your health; imagine how healthy these fortunate people could have been had they not smoked. This effect is observable even in the short term, as those who have recently quit smoking often experience easier breathing and are able to exercise more efficiently.
Making an illogical connection between ladders and tooth loss does not make the connection between smoking and disease an equally illogical one, as this has been supported by years worth of research and statistics. You’re much more likely to lose all your teeth if you smoke, as it can cause gum disease!

While nicotine may be beneficial, there are ways of administering it (like patches or inhalers used to help quit smoking) which do not involve exposure to the toxic chemicals and carcinogens in cigarettes.
While a beneficial effect on dementia from nicotine has been suggested by initial research, the link between cigarette smoke and cancer, gum disease, mouth tumours and skin aging has been long established.

The problem is, cigarettes are highly physically addictive…even more so than chocolate or bondage (though I’m sure some would disagree!)
While some people do use tobacco ‘moderately’ the addictive nature of nicotine makes usage very difficult to regulate, and it easily increases to excessive levels, especially in times of stress.
While too much chocolate will cause weight gain and adversely affect your health, it does have antioxidant benefits, while any possible benefits from cigarettes are far outweighed by their toxicity.

Drinking, smoking, driving; all legal. All dangerous. As is sarcasm :p
Gambling, while not exactly dangerous, is a leisure activity with some potentially very unpleasant consequences for individuals. Despite this, in recent years it has gained a lot of backing from the government, precisely in order to collect public money.
Even so, as far as smoking itself is concerned, the present government has made things as difficult as possible for smokers, without outlawing smoking altogether. It now takes a concerted effort to go and take a smoking break at work, evading as you go the billboards emblazoned with anti-smoking campaigns designed to prey on the conscience. Smoking remains legal to avoid a public outcry, but governmental departments have adopted another approach to discourage it: stigmatisation. In this way, smoking is in effect "allowed" less and less. While smokers are not breaking any judicial law, they find increasingly that they are breaking a social one.

The government’s agenda in carryong out anti-smoking campaigns is to improve public health and in doing so save money that would otherwise be spent by the NHS treating smoking-related illnesses. If people followed the advice and gave up harmful cigarettes, these funds could be directed towards other areas of social care which benefit the poorest members of society.
Anti-smoking campaigns do not specifically target the poor, although I fail to see how buying a packet of cigarettes is worse than buying food and shelter, especially when the idea of welfare is to support the person until they are able to find an occupation.