Well, here's how I see it. I understand what you are trying to say, it is not your (or anyone's) business to decide what other people should do with their lives, specially if it doesn't affect others. And, so no one (or governments) should intervene and regulate/ban sale of cigarettes. Would you feel absolutely the same way about all banned substances? If not, well you should agree that different people would draw the line differently.
> Would you feel absolutely the same way about all banned substances?
Yes, absolutely. If people want to ruin their lives it's not my responsibility to keep them from doing it. It's their own decision and all consequences are their own problem.
This is an absolutist view, while it is quite a compelling argument for certain extreme cases, I am afraid the world is never that black and white. Since we are talking about regulating/banning substances, let me try to point it out with a relevant example. While it might seem fair to say that if someone wants to ruin their own life by substance abuse, why should it be my (or the government's) responsibility to keep them from doing it. But, consider this, one of the growing problems right now in the US is opioid dependence and addiction. In these cases, these opioids are medication that is prescribed by doctors to treat acute pain. But, along with providing pain relief, this medication can cause opioid dependence and addiction over time. A sizable population of regular people who were just seeking treatment for their illness, unfortunately ended up with opioid addiction. This could just as easily happen to any of us or our loved ones. I can't speak for you but I would definitely want the government to step in, fund relevant research to study the problem, based on that perhaps regulate (or ban, if necessary) the availability and/or prescription of such medication because though it provides pain relief, it has unintended consequences that ruin lives of unsuspecting people.
Government regulation isn't necessarily always bad. There is no absolutist one-size-fits-all solution for all problems. Would I like the government to tell me what I can and cannot do, absolutely not. I would protest with you if I think government is overreaching. But, would I concede that there are certain issues (which might not affect me, but might affect lot of others) where the government has to intervene, of course, yes.
