In college baseball, it is generally acknowledged that RPI doesn't mean much until teams have played 20-25 games. Just not enough games involving common opponents until that many games have been played. For the same reason, who-played-who analysis that tries to discern differences between fairly comparable football teams after a 12 or 13 game season is destined to remain unpersuasive to the teams left out.
I think the committee made a very defensible choice even though I hoped to see how a Big 12 offense would fare in the playoff.