Why dont smokers in Casinos just go outside?

So Im in Las Vegas for the first time, have been the legal gambling age for a few years now, and I am just blown away by the people who light up ciggarettes indoors right at the table. Why do these people not understand that non-smokers are more bothered by the smoke than they are comforted by it. Wouldn't these people have the common sense and decency to just go outside once an hour to smoke- especially the one guy who lit up at a table of all non smokers?