This is an issue that needs to be addressed. Take a look at this thread.
The main complaint against smokers is that they really really stink. This is an old form of bigotry applied to the poor: that they're smelly and unwashed.
I even dated the daughter of a Beverly Hills millionaire when I was in college. Even though I was from a poor background, I was very academically accomplished and a go getter, so was socially admissible. She would worry that poor people would be smelly and bring the topic up in a rather snobby way when going into non-millionaire areas.
As to tobacco smoke, they invented this new product called Febreeze, in case you haven't heard. It works. Tobacco smoke is not some malign spirit that lingers in the area until an exorcism is performed, as some people obsessed with smoke seem to think (though they don't offer these complaints about weed smoke, at least as far as I've seen in such people's rhetoric, and weed smoke is much stronger, stinkier, and ever skunkier).
Also, nicotine is an addiction, I've read as strong as a heroin addiction in some people. So it's a form of self-medication as any drug use is. Plus, it's way less destructive of your day to day life and family than alcohol is, which, if you think about it objective, is a hard drug in terms of its effects on people's minds and behavior.
So let's lay off the smokers and be a little more compassionate. The anti-smoker sentiment reeks of classism and snobbery and discounts real mental problems that smokers have.