I suppose it is based in that most people consider smokers disrespectful.
you are standing in line, waiting for the bus and someone in the line lights a cigarette without any regard for the other people in line, that, while perhaps not considered so by the smoker, can feel pretty disrespectful.
and frankly if you try to point that out to the smoker it is not unusually you get a rather rude and dismissive response.
I, myself have rather serious asthma because my parents wasn't careful with their smoking when I was an infant.
I am more damaged by their smoking than they themselves ever was, and that is because of their heedless actions.
and on top of that, of all the smokers you know, how many of them thoroughly extinguishes their remaining cigarette butt and actually but it in the dumpster?
I know of no such smoker, they just fling it away, tossing it to the ground, and many smokers smoke several cigarettes per day, think of all these filtered butts that cant be decomposed in nature just being strewn about.
besides, smokers are considered rather expensive for society aswell, there has been a lot of argument here in sweden about whether or not smokers should be allowed health care at the expense of the rest of society, since they are much more likely to become seriously ill.
while of the smokers defend themselves with the fact that they pey more taxes than other since cigaretts have such high taxes, but then the other side claims that sum is not nearly enough to compensate for the hospital costs and so on and so forth.
there are more respectfull alternatives, that's all, for example, if you really need your nicotine there is always snuff.
other don't get harmed when you use it, only you but that is your choice.
I don't know what it is like elsewhere but in sweden, snuff boxes have like a mini stash in the lid where you can put the used snuff so you can dispose of it later.
now as a finnish, I actually don't hate smokers, there are many downsides to smoking, but I suppose if you are ok with that then smoking is your choice.
so it's ok as long as you show me the same ammount of respect by not smoking in my direct vicinity.
BTW. don't smoke when walking down a crowded street that is like THE most stupid thing you can do, pretty much 2nd hand smoking as many people as possible, I'm always amazed at these kinds of acts.