Man, I can't believe you are making me agree with Illiterate Impotent.
- No sports organization in the world does what you are saying. None. That's because often time divisions, conferences, etc., are not balanced, and you don't want to lose your best teams and have crappy teams in the playoffs instead of other better teams.
- In the NFL this year, the NFC East had 3 of the final 4 teams. Arguably the most profitable and prolific sports league in the world, and you would have just had one of those teams playing.
- You would have had UGA, Clemson, Utah, Kansas State, and Michigan in your playoff when it was clear by year's end those weren't the best team. Why not set it up so that the best teams play each other?