BYU coaches were terrified of Kansas' O which led to them putting together a super conservative gameplan. Just think about that one for a minute a Top 10 team was so terrified of playing a 3-6 team at home that the Top 10 basically resembled the the 3-6 team and tried to play keep-away rather than play football.
It was also obvious when they got down the field and then turtled to try to bleed the clock scared of Kansas getting the ball back instead of going and getting the touchdown needed to actually take the lead first and worrying about clock second.