Perhaps more important, almost no one smokes pot around other people who are not smoking pot. It being illegal and all.
The exposure to unwanted second-hand smoke from pot is so microscopic that I suspect people having an allergic reaction to other people's perfumes has killed more people. I suspect allergic reactions to pollen have killed more people. When someone says 'Your cigarette smoking is bothering me, please stop', people can say no. When someone says 'Your pot smoking is bothering, stop or I'll call the police', it's a lot harder to refuse.
Of course, the dangers of secondhand smoke at, at this point, grossly overestimated by the public. Secondhand smoke is an issue if you're operating for more than an hour a day in a room with smokers, like bars and stuff. I'm all for banning it indoors if anyone has to be in that environment.
But secondhand smoke is not an issue when someone is smoking outside next to the doors you have to walk through four times a day, for a grand total of being within ten feet for them for five seconds while outside, and attempting to banish smokers halfway across the street or entirely from the property is just assholery. You're more likely to get cancer from the commute or the PCBs in the paint in your wall.
And I say this as someone who has never smoked in his entire life, but is willing to say 'Okay, fellow non-smokers, we stopped our risk from that shit. They can't smoke in the room I'm in and fill it with smoke. And now we're just doing stuff to smokers out of spite.'