Smokers simply do not respect those who do not smoke - and they smoke wherever they want, even in front of children.
Some don't respect, while some actually do; it's a thing of personality. I have met some smokers who, before they smoke, will ask you a question if you are comfortable with it or not, and if you are not, they can quietly move to somewhere they can do it. There are also some who smoke even while walking on the street; they don't even care about who is not comfortable with it and who is. It's not all smokers who don't respect others space.
Like me I dislike the smell of cigarettes I won't even tell you to leave or wait for you to ask me if am comfortable with it I can only stay if it is marijuana you are smoking because I classified it as a harb I believe it won't be as dangerous as cigarettes.
Those who smoke on the street while walking are mainly insane people they are not mentally ok I see those who smoke on the street as irresponsible people even if we should smoke let's it be responsibly.