By profession, I am a game designer. A significant portion of a game designer's job involves coming up with systems, and then figuring out how exactly people are going to exploit, get around, or simply abuse them to get ahead. And people do cheese the system to get ahead, even when there's nothing at stake except bragging rights. That's why there are so many companies making anti-cheating software out there for multiplayer games. It's because there are that many people cheating. Doubt me? Hang around video game forums for a while. You'll see impressive evidence.
Now, let us consider the BCS. By announcing the basis of its magic formula, the BCS has saved the coaches involved the potentially difficult task of reverse engineering the system. That means the system, and all of the flaws, loopholes, exploits, and potential cheats are exposed, and this time, it's not a question of who PWNZ0R3D whom. There are umpty-million dollars at stake here, far more incentive to hose the system than the chance to jump three spots on a ranked leaderboard on XBox Live.
I'm not saying that anyone deliberately jerked with the system in order for Florida to make its Crash Bandicoot-sized jump in the BCS standings this week. But if you put the system out there, smart people will figure out how to exploit it, how to adjust their votes up and down to get the results they want for their schools and their conferences, and the system is worthless.
I'm just saying.