Kurgan, you are right, and being a BYU fan/Mormon, I think religion matters very little in the case of Jimmer.
Sure Mormons like the fact that a Mormon is in the NBA, but I think what you are seeing are huge fans of a college program with a hugely popular athlete that put a less frequently celebrated program on SportsCenter night after night. You know and probably have experienced the draw of college sports.... it's a like a religion for a lot of people. What Jimmer did for that college program, taking them into the sweet sixteen for the first time in like 30 years was HUGE in that little town. Was he insanely popular because he was Mormon? Of course not... so was everyone else. Jimmer is a college hero and not a religious hero. I can't explain the rabidness of a few fans... it boggles my mind as well, I root for him as much as any BYU fan, but don't understand the constant need to demand he gets respected. But I truly think that the love for Jimmer is rooted in a bit of nostalgia of the games that he dominated in college and the wish to the same thing happen at the next level.