Back in the day as an undergrad, I actually had a couple of classes where we could smoke in class and in the upper mezzanine of the basketball arena during games. LOL - I must be old! At any rate, later in my career while working at a school, I served on the board that made determinations such as these. The problem with smoking (and why we banned it from campus) had nothing to do with the smoke - the problem was the mess left behind by smokers and the cost associated with cleaning up after them.
So you banned chewing gum also, right? Since it was a litter matter.
Let's be honest. Who hasn't seen cigarette butts scattered around outside of buildings? Inconsiderate and sloppy smokers deserve to be fined if caught.
As for second-hand smoke causing death, I have yet to hear the proof. Has "second-hand smoke" ever been cited on a death certificate as the cause of death?