Reasonably speaking, it's not treating
cigarette smokers as
second-class citizens by expecting them to not throw cigarette butts out the window. Why?
Cigarette butts are BURNING GARBAGE.
Are we expecting something special of smokers by asking them to not commit crimes such as
littering or
arson? Of course not. If I set some paper on fire and threw it out the window of my
car, of course people would be upset. I don't care about your
secondhand smoke, and far be it from me to regulate your
personal habits. You still can't
hurl fire at me and expect me to take it sitting down.
Not moral regulation. Just simple reasonable behavior; there's no need to insult or condemn smokers; it just happens that non-smokers are not likely to be throwing cigarette butts around. And, obviously, most smokers would not engage in such activity, blah, blah blah. People who throw gum on the ground are almost as bad.