The thing is, the government doing that is literally the government taking away your freedom to do something that you want to do. I like living in a country where you're allowed to do what you want. Sometimes I really enjoy a smoke at night when I'm sitting alone just thinking. I sure as hell could sit out there in the cold and think without the cigarette, but it's what really makes the experience. That's pretty much the only time I smoke. It takes me over a month to get through a pack of cigarettes -- I don't even know because they go stale before I finish them and I have to buy more. Anyway, the point is that I don't want the government that's supposed to improve my life telling me what to do, or what I can't do. I feel as a human being my body is my own land and I should be able to do with it as I please, even if that includes the occasional bad stuff.
Once again, I make the point that in the case of cigarettes, its not a bad thing that only affects you. Other people have the right to not breathe in other people's smoke.
If my bad habit was sniffing tubes of anthrax and I started sniffing it in crowded subway tunnels, I think there'd be government involvement. An extreme brown townogy, but regardless its correct.
I do agree though, if your bad habit has no effect on anyone else, then go ahead.