I think it is a little too easy for non-smokers to question why anyone would smoke. While I discourage anyone from smoking tobacco, there are a lot of reasons why one would smoke. Many find it pleasurable. It is very addictive — at least in part because of its pleasurable effects. It is also a soothing habit to many. And it can play a social role. The last two are particularly true in any setting in which one is cooped-up. Whether your a contestant on “Hell’s Kitchen,” spending time institutionalized, or a courtesan a brothel, when you have to spend almost all your time in a (relatively) small space with largely the same people for an extended period then smoking becomes a contagious social habit.
So hate the smoke but not the smoker. I would nudge a friend to quit smoking as strongly as our friendship would allow. I celebrate those who manage to refrain or — even more praiseworthy — to quit smoking and I prefer to avoid cigarette or cigar smoke, but I understand why people smoke and don’t condemn them for it.