I wouldn't mind the outdoor smoking thing so much if I didn't see butts everywhere, on the ground, in the gutter, filling planters, all over the beaches, scattered all over the sidewalk outside buildings, being flung from cars, dropped, stepped on, ground into ornamental brickwork, and, in the rain, stinking with the stench of a thousand ashtrays.
Ever get hit with a flung, unextinguished butt at highway speeds, where the thing breaks into sparks and scatters over your nice finish? And you wish, for a fleeting second, your car had James Bond-like forward missile launchers? Or worse, getting hit with one while on a motorcycle?
If so many smokers weren't such SLOBS about dropping the things, or about letting out a cloud of rancid, putrid smoke from their nostrils (always so charming, that, about as much as flatulence) just as a nonsmoker passes by and is forced to choke on it...then they might not have been noticed to the point that they were being banned from public areas.
To equate this to guns, it'd be as if people were randomly pulling out their weapons and firing them (say with blanks) on crowded streets, causing a loud, unpleasant noise that bothered other people and could possibly do longterm damage...and were leaving brass everywhere. They don't, of course. But smokers do the equivalent.
