I agree, in general. Although, I can tell if someone lights up in the car in front of me at a stop light if the wind is in the right direction.
In a crowd, it's a little more problematic. Like an outdoor concert, or tailgating. If I'm at a tailgate, and the people next door light up a bunch of cigarettes or cigars, then it's a problem and they need to stop.
One smoker 50 feet away is not a problem and a total ban on campus seems unenforceable and unrealistic. But just outside an entrance or in close quarters is not.
It's not the odor or the cancer I object to. The sun can give you cancer and body odor is more offensive that smoke. Cigarette smoke triggers my athsma. Period. You have no argument against that. I'll be glad when I can go to a bar and not feel like I can't breathe or wake up coughing up slugs of phlegm. So secondhand smoke is a danger whether you believe it or not, no matter where it is.