You are making a lot of assumptions. Bowl game attendance is influenced by a lot of factors. What bowl you are going to, it's location, your opponent, the date & time, etc. Appalachian State would get better attendance than BYU if they played in the Cotton Bowl and BYU in the Poinsettia Bowl. It doesn't mean they travel better.
I remember when Utah played Boise State in the LV Bowl a few years ago. Probably 60-70% of the attendance were Boise fans. Should Utah be given credit when the opponent sells the game out?
You made a big assumption with no data to prove it.