I can give his reasoning, but I didn't want his argument to color or affect any future commenter's thoughts.
His reasoning - from what I can recall, was that by extracting teeth, one effectively pushes the bite back. When the jaws are advanced forward, bite will not abnormally protude (described as a "baboon face" by one orthodontist) forward. While aesthetically all may initially appear fine, he said that by effectively pushing the bite backwards, you're not maximizing the space of the airway as much as possible.
This argument functional and not aesthetic, unlike yours. While *kind of* understand his argument, I don't understand yours but would like to. Could you explain how lateral advancement leads to a smaller looking lower-face?