Smoking is not healthy and smokers should be considerate of others when engaging, but let's be real about it.
That sounds like rationalization of your own actions.
Sure, the environment in cities isn't pristine, but it is a lot better than several decades ago, and multiple bans on noxious substances were needed to clean the air up a bit. When my mother was a kid (1950s), smog was so severe that street lamps had to be lit during the day. Ah, the beauty of burning coal in the middle of a city without any filters.
Maybe, if you are a smoker, you are just so used to smoke that you don't realize how disgusting it is for non-smokers.
A friend of mine quit and, after a few months, as his sense of smell slowly came back from the dead, sincerely apologized to everyone else for smoking around us. He said that he, as a smoker, just didn't realize how pungent and revolting the smell of tobacco smoke is to others.
Once upon a time, people threw all sorts of garbage in the streets, including rat carcasses and what have you. It was the norm and people complaining about it were considered sissies.
In the 1900s, this was already beyond the pale, but "everyone" was fine with black soot from coal-fired furnaces covering everything, and with car engines smelling to high heavens.
Nowadays we don't tolerate either, so smokers are starting to be targeted.