DH and I spent a long weekend at WDW and POP a week ago, and I couldn't believe how much smoke I inhaled. I put the responsibility squarely on WDW for not prominently posting the smoking rules in the parks, for not enforcing the smoking rules in the parks, and for not having designated smoking areas at the resorts (once again, prominently posted and enforced!)
Our first morning at POP, the patio outside the foodcourt was a haze of smoke. It was disgusting--we could not possibly have eaten outside. I realize the resorts don't regulate smoking outdoors, but they need to--there are way too many people concentrated in certain area (like the food court patio) to think that people are not affected by second hand smoke.
I am an ex-smoker, and I think most smokers don't realize how truly awful cigarettes smell to us non-smokers (speaking from my own experience as a smoker!).

The clothes I wore at POP and the parks actually stunk of smoke--I could smell the smoke when I was loading the washing machine at home.
I do think MOST smokers would follow the rules if they were clear, prominently posted, and enforced!