Isn't that the truth, Greg!
The "no DIY cords" crowd got a boost from OSHA, and have applied the 'pendant cord' requirements to such efforts. That is, the box needs to have the connector attached using a hub (lock nuts alone aren't enough) and a proper strain relief connector. Such a requirement is found in the NEC under 'pendants.'
"Proper" in this case meaning one of the types with rubber grommets; Romex connectors are listed for use with flexible cord (look at the box), but not for this application. "Pendant" connectors have a much more rigorous strain relief test.
The next issue, of course, is the OSHA desire to have all cords, on all construction sites, be GFCI protected.
I had assembled a rather nice such center, and had presented it to a certain very prominent 'code authority,' a man who has made a career out of taking pictures of falling-apart 1600-box assemblies. He conceeded that the effort looked worthy ..... until, years later, he sent me a link and asserted that now ALL DIY assemblies were banned.
Alas, the 'link' was to the entire Code of Federal Regulations, and I have yet to find whatever it was he was citing.
I fail to see where the AHJ comes into this discussion. Building permits, after all, are on the building - not the builder. I don't believe that a contractor's tools are under the jurisdiction of the building inspector. If he doesn't like it, he has the same right as anyone to call OSHA- no more.