As being on both sides of the coin, smokers have every right to smoke in the parks in their designated areas. I also have to admit I've almost never seen anyone deviating from that. Cast members can't catch everyone and I try to be very observant. "We" are actually very conscience. I always felt uncomfortable smoking in areas that everyone could clearly walk by. In that instance, I do get the griping, but don't lecture the smoker, lecture Disney for placing them in areas where a lot of people are walking by. I don't judge anyone for drinking, marijuana, etc. It's an unhealthy habit but it's their right to smoke. And no one better ever grab a cigarette out of my mouth unless you know me VERY well. That's rude and not right and a HUGE violation of personal space. I don't care what you're personal feelings are towards smoking. It's not up to you to decide what is right for me. I appreciate the concern, smoking kills, it does, but it's mine and others right to choose to do it and we have every right, as long as Disney allows, to smoke in the park. I actually feel a bit strange smoking IN the park, but that's me. I can usually go all day without and be just fine though.
And yes, the number of smokers is declining, but I think many here would be surprised at how common it still is. It also depends on the area you are in, IMO.
Smoking isn't going away anytime soon. And like others have said, it's very common elsewhere. Go to Paris, they smoke everywhere at Disneyland Parc, I've seen that said so many times. It's different everywhere you go.
How about just simple respect for others. That kind of thing works both ways. We're losing sight of that in many ways.