Also, as noted, foreign guests and cultures do not have the same feelings about smoking as we do in the US. And, as WDW is an international destination resort, this should be considered.
For a large outdoor area, such as a theme park, banning it outright is probably not the best operational decision. As I said, people will flaunt the ban. For example, smoking is banned at the resorts on the balconies, but people still do it. People who smoke are not going to stop simply because they are at Disney. So, you need to account for it, reasonably.