The racks where I work are a mess too. I once took a tour of an EMC location in Boston about 5 years ago and they had an impressively wired computer room. They tightly controlled how wiring was done and everything had to go through a wiring group for approval and for installation. It was nicely colored coded, channeled well, all the wire cut to just the right length, etc.

It was probably a real pain for those needing new equipment to be installed, but they sure kept a tight ship on it. At least that's the way it looked on the surface. Maybe there was a messy room behind a closed door somewhere.