conduit for ground in metal shop
Yeah, that's wrong. The inspector ought to know better; clearly does not inspect a whole lot of commercial installations.
Gently stand up on the point and show him the code, and leave him a path to keep his ego intact (that is less than you pulling a bunch of pointless ground wires).  That's part of negotiating.
By the way, if you do pull the trigger on pulling ground wires, the ground wires go to the boxes not the receptacles.  They land on a 10-32 ground screw (which doesn't need to be green), which goes into the hole in the back of the box already tapped 10-32.  When bringing a ground to any metal box, you must go to the box first. Once that's done, if you also want to bring ground to the recep, you can do that also e.g. via pigtailing. #1 mistake I see grounding metal boxes.
In cases like yours, where the recep will have hard flush metal contact between its yoke and the junction box mud ring or domed cover, that is a valid grounding path and ground wires are not needed.  So remove that little paper square that captures the receptacle screw!
On switches it's even easier, you don't even need to remove the paper square and you only need screw-head contact with the yoke.