I have friends who are very close to the program and will give you my 2 cents worth, from what I have heard.

Part one of the problem: Kyle is very loyal, defensive minded and data driven, but he perseverates on turnover margin.
This lead Kyle to build from the lines out and set the basis for ball control and tough defense.
Part two of the problem: going from the MWC to Pac uncovered 2 things, Utah didn't have Pac-12 depth or pac-12 caliber coaches across the board.

Part 3: For years, Utah did a TERRIBLE job recruiting and coaching QBs.

With that as the background here is how I have heard it go down:
Norm Chow: Left for a HC job-can't blame him for that-but you could argue he was the best of the bunch. Utah wasn't prepared physically to compete in the Pac-12 and Jordon Wynn could barely throw the ball 20 yards. Norm won with John Hays for crying out loud.
Brian Johnson was over his head. He knew the offense, but couldn't break it down and make it simple enough for the players.
Dennis Erickson: Utah moved the ball well with him as OC, Wilson was a freshman with him at the helm, but Erickson didn't want to be a coordinator anymore and there was a feeling among people close to the situation that he was not approachable for the players and there was a coaching gap there.
Christensen: singlehandedly almost brought the program down. Many of the coaches on the staff threatened to leave if he wasn't let go.
Roderick: From people in the booth with him--Terrible at calling a game, totally insecure and couldn't make a decision, and was also a terrible QB coach.

Ultimately it comes down to Whit, and I THINK he has finally figured things out. He knows the only thing that has kept Utah out of the PAC 12 championship game is the serviceable passing game. He has upgraded the coaching staff-- we have a great O-line coach in Harding, and I love Guy Holliday--Thank you. Huntley represented a change in the QB recruiting, using a lot more resources to find one and recruit him hard. I'm very happy with our last 3 QB recruits.

I'm buying what TT is selling. He's shown that he can install his system at a higher level quickly and efficiently, but I think people will be surprised at the lack of wholesale changes. I saw a breakdown that EWU only ran 3 more plays a game than Utah did last year, and I still think you will see balance on offense in the realm of 45/55% one way or the other.