It is personal opinion when you go on to say "Some homes do reek of cigarette smoke...."
The word "reek" is a personal opinion word used to conjure a negative idea of a particular smell. My comment went on to say that others disagree with that opinion because they either don't notice, don't care, or like the particular smell.
I'm a smoker and I can smell tobacco smoke - the only time I find it offensive is after some idiot dumps whiskey in an ashtray and then it isn't disposed of immediately. But I think that is more because I don't care for the smell of whiskey.
Please note I did not use the words stench, filth or reek, when I expressed my dislike of the smell of whiskey.