Cigarettes look like a justifiable product at the level of "we roll leaves in paper," or "we give you a drug with side effects no worse than some other psychoactive drugs," but when you get in to the details of how it was actually done (carcinogens added above and beyond the smoke itself for the purpose of enhancing addiction, marketing designed around the well-known "trigger" stimulus response of relapsing drug users, denial of the effects to offload health liabilities to state insurance) it's no longer anything but an errant time in our history which will hopefully not be repeated. It is the prototypical example of the profit motive departing from the public good.