The difference is that a candy bar only kills the person who is consuming it (and kills them much slower than a cigarette), while the cigarette kills the people around the smoker too.
What people find disgusting differs from person to person though, that's why it's the other way around, if you don't ever want to see anything you find disgusting, you have to stay at home or plan your routes extremely carefully, possibly wear blinders.
From your link, "The study doesn’t cover the many other ill effects of breathing somebody else’s cigarette smoke, of course, which include asthma and possibly cardio-pulmonary disease."
My anecdotal evidence says otherwise. I get a headache whenever I'm near a smoker, even if I didn't know they were smoking until after I got the headache (I have a bad sense of smell and sometimes I don't smell it).
