As a non-smoker who has encountered careless smokers on the dance floor (one which, fortunately, didn't cause me any physical injury), I'd much rather people keep their cigarettes off the dance floor.

Sure, I didn't get angry when some guy's cigarette was on my arm for like 5 seconds, during which I was trying to figure out what the hell was causing that unbelievably painful sensation, nor did I screw him over when he went, "Ouch, ouch, ouch!", looked at his cigarette and then looked at me to ask if I was okay. The burn mark took a few months to go away.

A couple of days ago, some guy at a club almost waved his cigarette right in to my eye. If I had caught up with him, he would really have gotten it.

Granted, there'll always be some careless people among the multitudes of sensible people, and maybe imposing a regulation banning smoking on the dance floor or in clubs may be overkill. However, given that not smoking won't kill you, but your smoking may well seriously injure me, I think my point of view is entirely justified.