They were ALL blue bloods (except for Virginia Tech in 2000)...
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https://en.wikipedia.org/wiki/BCS_National_Championship_Game#Records_by_team
The BCS system allowed only 2 teams to play in a meaningful bowl, and two-thirds of its selection formula were based on "biased human" polls. The computer component was only one-third of the equation and barely moved the needle at all.
So you had 1 meaningful bowl game in the BCS era, while the rest were just post-season exhibitions. Now you'll have 6 meaningful bowls, with the rest as meaningless as before.