In my book it's because we see more toughness out of his teams. They bounce back from a loss. They keep fighting even when they lose players. They don't quit. Rose appreciates his fans. He has underachieved a couple of times, but his teams are consistently competitive, and rarely do we feel like the wheels are coming off. His recruiting has been spectacular, to the point at which we feel like he is building the program, and not hurting it. He has not been the perfect coach, but he has made BYU basketball relevant, and kept it there.
Rarely are we embarrassed by BYU basketball. And yet we seem to be consistently embarrassed by BYU football. And when Rose looses, he doesn't say he did everything right and the players just didn't execute well enough. The comparisons between Rose and Bronco happen a lot because they were brought on at the same time, and the programs were in similar conditions when they arrived. But Rose has been much more consistent in building and maintaining his program, IMO.