I clean frames as well as glass as standard and not optional
So do I stephen, however, you will find that after a while the frames will "gray up" in parts of the frame no matter how well they are scrubbed.
As the the mechanic analogy, it is perfectly possible to get a car that is hand built and crafted. If you have the money you will find them. As for using a buzz gun as opposed to arm muscle, I wish they had when they put my sump plug back on as they cross threaded it and had to re bore the sump, which they did badly I might add. Had to take it back and loose a days work while they re-did the plug.
Your average mechanic will work away like a zombie and get confused if he cant plug something in to do a job.
Same as the average WFPer, never learnt the skill of trad work and gets confused easily if he can't splash water at the window.
By the way I'm WFP and love it, but I'm not so arrogant as to believe that it is a magic stick and can fulfill every requirement. It is a tool to be used.