A lot of athletes smoke, but they don't do it when they know the "image" is at stake.
And yes, college students who want to compete, will put the cigarettes down if they want to play. Just like they do for baseball, football, and all other sports.
There are two sides of disc golf; The leisure side and the competitive side. We are talking about the competitive side. Leisure golf will always be ripe with smoking, drinking, etc. Just as other sports have a leisure side with the same attitude. However, professional sporting organizations, who mean to see the growth of the sport, have to create standards by which all athletes will follow. These standards are meant to both regulate the fairness of play, such as no taking steroids, equipment standards, etc. And to preserve the image of the game to the outside world - football, basketball and baseball players all coming to the stadiums in dress clothes, and... no smoking during the event. The NFL, NBA and MLB do not tell regulate smoking by their players when they are not "representing" the team, e.g. on their own time, eating dinner at a restaurant, for example. But if the event is sponsored by the organization, there is no smoking by the player, etc.
Again, this isn't a "rights" issue. Smoking isn't a right, it's a privilege. Smoking is not protected under any law. It's just something you can do which isn't illegal. So telling someone they can't smoke at an event, is not a violation of anything. Certainly not someone's right.
If the college students feel so strongly about smoking that they don't want to play because they can't smoke, then they can play leisurely as long as they want. They like smoking more than disc golf. Which is, in fact, their right.