Texas finished 8-10 in conference. So did Pitt, Fla St, Clemson, Oklahoma st, Michigan, Oregon St. Kansas St. All in leagues loaded with talent. I guess they all deserve a bid
Not every win is equal. Not every loss is equal. Not every conference record is equal. Texas played 5 top 20 teams twice each in conference. Their "easy" conference games were OK State (RPI 45, BPI 30), K State (RPI 83, BPI 76), TCU (RPI 126, BPI 62, 13-0 non-conference), and Texas Tech (RPI 172, BPI 142). Texas Tech would give the top of the MAAC and the OVC a run for their money. So would TCU. They won a combined 7 games in the Big 12. Texas would have won every game by 10+ in the MAAC, and they are barely hanging on because they played in the Big 12 and lost 10 games in conference.
The NCAA committee has to pick the best 36 at-large teams they can. Not the 30 best teams and 6 teams that would make the best underdogs.
Bottom line is Texas, OK State, Miami, NC State, Indiana, Xavier, etc., are better than most of the smaller conference teams with 20+ wins (or whatever arbitrary number).
Ask a Vegas oddsmaker who would have better odds to win the tourney, Kansas State or Iona, then remember that K State finished 8th in the Big 12.