Here is my humble opinion on why having playoff games on-campus is essential:
Everyone always talks about how important it is to fill seats in these games (a la the ncaa tournament's attendance problem), and they are right. nothing kills the playoff mood quite like empty seats. Of course, it is possible for some fans to travel to the game if they are given enough time to prep, take off from work, book flight, etc. BUT it is nearly impossible for the most important fans to attend these games. I'm talking about students. It is a logistical and financial nightmare for a student to attend any football game that is not on-campus.
For example, the gator bowl took place on monday january 3rd. the very next day, a mere 18 hours after the game which took place halfway across the country, classes started. Between the cost of travel (which is massive since you are buying tickets so close to the day you are traveling), hotels, and missed class time, traveling to this game is virtually impossible.
The same thing happened with the final four. I knew someone who attended, but they couldn't afford plane tickets and a hotel. They drove down, stayed in a hotel miles outside of new orleans, and then left right after the game. They ended up missing at least 3 days of class (it was a while ago, i can't remember the exact number).
In my humble, and worthless (at least to the people who will ultimately decide these matters) opinion, it is, for lack of a better term, horseshit that these games will be played hundreds of miles from the most rabid portion of the fanbase, simply because they do not have the financial resources to attend games so far away.