There is a difference between the singer who has a genuine affliction, such as asthma or as mentioned for Kendall on the one hand, and the petty and precious on the other. I really object to the "holier than thou" in so many areas of life. As it happens, as I have been longer and longer a non-smoker, I do find it less and less pleasant to be too closely breathed on by too heavy a smoker (and would find some problems now in kissing a heavy smoker be she never so beautiful). But, hell, live and let live (or die).