I guess confusion at mins is the concern. If you are at mins bar alt and your rad alt tells you you have another 100 to go, it would be stupid and unprofessional, and downright dangerous, to continue decending, on the other hand, if you are getting your bug light and you still have another 100 to go bar alt???? If you are aware of what the terrain has in store for you and have your act together, the extra information is indeed handy, but as an SOP, playing to the lowest common denominator, I see confusion a possibility at the most stressful time during the approach.