I smoked for a little over a decade, then quit about a year and a half ago. Gave myself a month to smoke as much as possible before the quit date. Smoked a pack and a half some days. Figured if I was gonna stop, I should get all my smoking done before then. The first three days sucked. Really bad. After three days, smooth sailing. Sometimes I dream that I am smoking and when I wake up I think "Damn, now I have to quit again", but aside from giving me really wierd dreams I have enjoyed not smoking. It has improved my surfing, cycling, and training.
My instructor smokes and so do a lot of the guys at the dojo. Hell, we've even smoked in the dojo before, but not so often and definately not while anybody is training. I let my friends who are smoker smoke in my house and in my car. It just doesnt bother me so much.
If you want to smoke, then you should smoke. If you don't want to smoke then quit. Thats all you have to decide. It is not a moral question, at least not to the degree that most people want to make it.