MCs often don't know about Retro because Retro grew out of the efforts of the Catholic Church. Your typical licensed IC is generally deemed to not have the training to deal with issues of religion or spirituality so the licensed counseling camp and the faith-based camp tend to stay fairly far apart, despite the fact that many MCs have deeply held faith positions.
The exception to the 'not trained in religion' thing is if the counselor is what's called a Pastoral Counselor, meaning that their psych training occurred through the auspices of a seminary concurrent with courses in theology.
An analogy would be how come your dentist doesn't know much about physical therapy when they're both health issues.
The trouble with having an open mind is that people put things in it.
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