Shalomtoyou-
I think you mean live and let die.
But seriously, I don’t think live and let live is a Jewish concept. Kol Yisrael areivim zeh bazeh- we are responsible for each other. If someone is in physical or spiritual danger (and with smoking it may be both- dangerous and halachically assur) then it is our responsibility to try and help our fellow Jew.
Also, having a debate on whether a particular action is assur or mutar is something we do all the time in other areas of halachah. We don’t say live and let live, but we try to uncover the truth. I don’t think we should pretend to not care about the halachic ramification of smoking just because it’s a sensitive topic.