Yet, a valid argument as well. Cigarette smoke dissipates outdoors and unless someone is blowing smoke right in your face, the harm from second hand cigarette smoke is no worse than any of the other countless sources that emit carginogens also floating through the air, especially with all the open air foodstands and restaurants in Negril that are cooking meat over charcoal.
I do agree with you, however, that cigarette smokers need to be considerate of others around them. I only smoke on occassion when I have a few drinks, but I would never light up indoors or even in an open-air restaurant. It's not that difficult to step away from the crowd. And if I see someone throwing their butts on the ground, I typically speak up.
As far as the smell is concerned, I'm not sure we want to get in the business of banning things just because we are offended by the odor. That is a very slippery slope.