bochuratheart -“Smokers smoke so that for each puff they take, they can be Mevatel a Mitzvah Aseh de’Oraisso of “veNishmartem Me’od leNafshoseichem
147.. y dont u tell this to rav kaduri,rav shach,reb moshe”
As far as the OP -it depends. If the guy is blowing his smoke right onto s/o else then it’s disgusting. If he is a few steps away -then I don’t see the problem. If it bothers you that much – move out of his area.
As far as the Gedolim Matiring smoking -I doubt they would Matir it nowadays. At that time noone knew about second-hand smoke. But nowadays we know there is such a thing and unless the guy Never (impossible) smokes next to s/o else -he is a Mazik. To be Matir smoking because of Hakol Doshin Bo is one thing (regarding V’neshmartem), but there is No Heter to be Mazik anyone!