No sorry, I should not say ban but "they should never be existed" as they are only a malus.
And I don't understant the "closed mind", in that way I'm probably next (a clean and eco world)...
You made the example of the banned drugs but oh yes look at the cigarettes, they aren't banned and they are widespread like a normal thing
You're trying to dictate someone else's life. That's not really right, unless their actions harm others (e.g. crime). Smoking usually doesn't harm people, at least not that a noticeable extent.
I'm pretty sure that we have other problems to worry about if you want a clean world. Smoking (i.e. smoke; disregarding cigars as litter) isn't causing that much pollution. I can't find any exact numbers however one should look at this.
If you have industries like lead smelting, mining and refinement in your area you would have probably seen quite a lot of smoke coming from them.