Has he ever publicly said one bad thing about BYU? If he has, I cannot remember it.
BYU is Utah's rival. Why would he publicly promote the team he recruits and plays against? He shouldn't promote his rival even though he went to school there. However, he should not say anything bad about the school or the administration either. And, as far as I know - he meer has.
Also, I know for a fact that at least in two occasions, he has privately told the families of recruits that the kid would be better off at BYU.