Can someone help me understand this...

You misunderstand. The AKC does not set the breed standards, the breed clubs do. This is who you have a disagreement with. From doing herding and field work is where the breed standard is derived. If the dog (in your case the GSD) does not have the physical qualities to do excellent field work then it does not meet the standard as desired by the breed club. Poodles are not trimmed to just look good, they were originally trimmed that way to facilitate their particular field work.