This team is young and lacks a PG. That is a potential problem for any team.
James and Johnson, the elder statesmen of the squad, have played well. The younger guys have not been consistent and, as it turns out, their games don't collectively make up for the structural and experiential deficiencies of the team (none of them have proven able to add post presence or PG assists).
Because the recruiting class was very highly thought of, and because such classes have recently meant relatively immediate success for teams such as UNC and tOSU, UT was over-rated from the get go. They were further elevated by a sched that was not so strong even where it appeared it might have been (UNC). Sometimes it takes a while for weaknesses to be exposed or for chemistry issues to arise after a strong start. It would appear that, while this team is talented, it is not made up of the balanced talent that the above frosh juggernaut classes were.
Barnes seems to have gotten eaten up a bit by the amount of talent, its limitations, playing time, etc. He has not been able to effectively help them build chemistry and responsibility. He has kind of lost this squad and they are not finding themselves. The loss to Baylor was a rollover.
This team has always been what it is: young and lacking in some positional integrity (no PG, spotty post play). They didn't choke, they got exposed. They'll be better next year, but a run at the Final Four may not be in the cards for a spell.