It's about the resume. Ohio State only lost to the #1 team in the country (remains undefeated) and they barely lost at Michigan (away game). They have wins over #10 Penn, #16 Notre Dame, #16 Iowa. They are the best overall program since 1990 with a top 3 talent roster. Not sure how another team beat's that resume. If Mich is ranked #1, then every team in the country should lose to Mich and you can't get a better loss than OSU.
UGA has a point - off game you can say and won the last two national championships but they are not a conference champion. They beat #9 Missouri, #11 Ole Miss, #21 Tenn with a close lose to Bama. All of their wins are by 7 points with only two games being single possession wins. Best resume in terms of wins.
Bama - beat UGA (1 loss team) and the best win of the one loss teams, Ole Miss (11), LSU(13), Tenn (21) but lost to #7 TU (who has a loss to OU). Bama also had a lot of close games to questionable teams (Arkansas for instance).
TU - Beat #7 Bama, beat #18 OU St, beat #25 Kansas St, lost to #12 OU (2 loss team), . They almost lost to a bad UofH team and TCU team (both are non non bowl eligible). TU has the worst loss out of the bunch and they don't have the best win. The only real win here is the Bama win.