Imagine that you have a habit of harming other people. Imagine that other people feel nauseous in your presence and can't stand your stench. And it's not like you couldn't be like everybody else. You are choosing to be toxic. What would you expect society to do to you? Lock you up? Maybe.
Actually, far from it. The German society--well--Deutsche Bahn, the German railway company, will gladly grant you more space to sit (with others like you), give you your own bathroom and many other perks. As you might have figured out by now, this is about smoking. In recent times, as German trains seem to be filling up for some reason or another, people in non-smoking compartments have a tendency to sit packed, filling up every seat, while smokers are often seen leisurely lounging in the pair of seats they have to themselves. I'm a bit mad about this because a harmful habit is what grants them this extra degree of freedom.
I am claiming that there is also no business argument in favor of having smoking compartments. Consider what happened after the recent smoking bans all over the world (and in Germany!): Bars and pubs ended up selling more. But I imagine that no-one is listening and that Deutsche Bahn, as so often, is asleep at the wheel. (As you might know, this only refers to the long-distance trains--Smoking was prohibited on regional trains a while ago.)