Since joining the WCC BYU has finished 3rd, 3rd, 2nd, and 2nd. Rose is 3-8 against Gonzaga during that time span. He still has yet to win a conference tournament in the WCC or MWC, even as the #1 seed. He has a 2-game losing streak against the Utes.
He got swept by Pepperdine last season, which is why some are picking BYU to finish 3rd again this year.
Now, I must emphasize that I think Dave Rose is a good coach and can have the job as long as he wants -- much for the same reason I think Bronco is a good coach and can have the job as long as he wants. And I agree that he has some good players in the pipeline and the team should be better over the next few seasons.
But until he can win the WCC and beat Gonzaga more than once a season, and win more than a single play-in NCAA game, I don't see how anyone can logically say he has done significantly better than Bronco.