I can think of 2 reasons. One is just a convenience to be in the seating location to hear changes performed in the configuration. A second would be to make MRC changes while sitting in the sweet spot. Of a course a laptop would work just as well with a long serial chord.

Many of have a computer already connected for serving A/V to the system; With this, I would love to sit in my sweet spot and play with M-Config / MRC using my wireless laptop...

Although, I agree with your point's premise - It really is just a convenience when it boils down to it. Never-the-less, a convenient tool gets used more often and more experimentally than otherwise -

ken