You want to increase attendance then hope that the CFP gets extended out so that every conference champion gets a shot. IF the Cajuns were playing to get into the CFP yesterday tickets would have been difficult to obtain.
Fans want to know that their team gets a shot at the grand prize. The chances of winning the powerball drawing are less than the odds of getting struck by lightning but people still buy tickets because they have as good a shot as anyone else. If there was a rule that Lafayette residents could play the game but were not eligible for the grand prize what would happen to sales? Same thing is true for Cajun football. Some people simple don't want to invest in a product that has no shot of winning the grand prize. Especially when there is an option less than an hour away that not only has a shot but has actually won the prize multiple times.