A "smoke-free" society is possible as technology continues to increase. Alternate methods for the consumption of tobacco already exists in the form of chewing tobacco. In the states where marijuana has been legalized their has been inventions of soft drinks and food products that contain the active ingredients required by the consumer. This same technology could be used for tobacco products thereby eliminating the need for actually smoking tobacco. Advancements through time could increase the taste and method of consumption to the point that smoking would become undesirable in any fashion.
If you look back in history it has been proven that prohibition does not work, a person will decide what they want to do, sometimes even if it makes them a criminal. Subjecting society to terms that aren't acceptable for the population only creates problems. It is far better shift opinions, rather than trying to protect someone. After all the view of smoking has been severly altered over the last few decades.
There have many political attempts, especially recently, to make society completely smoke and drug free, but this is an attempt at changing hundreds of years of society and culture. Society as a whole is never going to be healthy, no matter how much we encourage it, so we must allow people to do what they've always done without guilting, shaming, or especially making anything illegal.
I do not believe that a "smoke-free" society is a real possibility. Of course we could make smoking punishable by death and that might do it. Other than that, there will always be someone smoking something somewhere. If it is not legal, they will still find a way and will just hide it.
We cannot eliminate smoking for a variety of reasons. They vary from "people are going to do what they're told not to" to the blunt fact that it is addictive and some people will be unable to give it up, all in all it's not a plausible goal to have, even if it's a good one.
As long a smoking remains legal, there will not be a smoke free society. There is nothing wrong with smoking as long as smokers take responsibility for their actions. Obviously, smoking is detrimental to people's health, but that does not mean that people should stop smoking altogether. People should be allowed to enjoy smoking.
A smoke free society is most likely unrealistic and will not happen anytime soon. People love their cigarettes and cigars. It starts with one than because an addiction where they are chain smoking and throwing all their money down on it. It would be unfair to have that many people get excluded places as well, so I do not see it happening soon.