It's religious freedom (BYU wants a lot, but doesn't offer their students much), it's social drinking (important for building relationships both within the company and with clients), it's stigmas about polygamy (false) and large families (true), it's unequal leadership positions for females as compared to males, it's fairly recent policies which discriminated against blacks, it's worries that an LDS employee might reactivate their "mission mode" and be uncomfortably forward about their religion in the workplace, etc.
Like I said, an interview could do a lot to relieve most of those concerns. But if you're just another resume, all those things could work against you...