most other coaches much prefer a game where all they have to do is pound the rock. Successfully running the ball burns clock, does not risk a sack, does not risk an interception, and wears down the opposing defense. So, sure, I'm certain both Grimes and Sitake would love to just pound the rock.
But Utah has a great D-line. If you want to beat Utah, you have to throw the ball. It's why Wazzu is a much worse match up for Utah than UW is. It's why Utah has struggled more against ASU than Zona. It's why Utah can be a mediocre team but consistently beat Stanford.
And if we're going to get the passing game going on week one, which we have to do to win, than we might as well keep it going for week two. Hopefully this will be in combination with a surprisingly strong run game.