It is not government's job to nanny adults over the use of a legal product. If they tried to make it illegal, I would object on principal, even though I despise the stuff. But when the addiction overwhelms the concern for the health of one's own children, it's time to rethink it.
My Grandparents all smoked, my parents all smoked and all of my early adult relationships smoked. None of us kids ever smoked. I don't have any health issues that could have been caused by cigs. I have a real hard time with the notion that smoking around kids is harmful based on my own experience.