March Madness expands the field in basketball, but there are still controversies over who should be included in the field. And despite the Cinderellas who achieve upsets, the Championship game is usually between two teams from the power conferences, Gonzaga, Butler, and George Mason aside.
The NCAA today uses an extended football playoff system in division 2, so the argument about over-stressing athletes is not their concern. It's a flimsy excuse that affects a very small number of teams. It's money and the bowl system and sponsors that are being protected.
Expanding the championship to 8 teams and three games will not remove the controversy over who should be in the final 8.
Certainly true, but in an enterprise with 5 strong major conferences, 8 seeds is necessary and will be instituted as soon as sponsors can figure out how to monetize it. You will see, however, a conference like the MAC or others bidding to become the 6th auto seed. Rothlisberger is a prominent MAC alumni, for example.