"the individual makes a poor decision which affects the individual" - except in the case of smoking where the poor decision also affects anyone else in the vicinity of the smoker, including those who have chosen not to smoke.
The smoker is smoking; a poor decision that affects them. You're in a smokey bar; a poor decision that affects you. The only difference is the smoker isn't complaining. There's no sense complaining about a situation one puts themselves in; there's even less sense in making laws which attempt to keep people from putting themselves in said situations.
A private establishment could force compulsory games of Russian Roulette for all I care. As long as there's a sign on the door.