Earlier quoted context omitted.
And they should be able to do so. We are free people (I hope). If one decide to buy tobacco, it's his own responsibility, and he should have the freedom to do so.
I don't have a strong opinion on this, but if you really believe that as an absolute, how do you balance the harm to society? For tobacco, harm being costs for increased health care, health impacts on non-smokers, and frankly the simple impact it has on the happiness of those subjected to your freedom.
Smokers are net over-contributors in most countries, cigarette taxes vastly exceed health care costs, in no small part to shorter lifespans of smokers and often quick deaths.
> health impacts on non-smokers
Maybe if you work in a smoking bar/restaurant (which is your choice) or live with someone who smokes inside.
> the simple impact it has on the happiness of those subjected to your freedom
I'll worry about that when society starts extending the same courtesy.