Guitars & Cars are apples and oranges and if you had any idea of the curriculum of becoming a luthier you would find repair at the base of study. I think if you took a minute and researched you would find that the people at Fodera, Sadowski, and the likes service their own instruments for there clients!Roger Sadowski was a repairman before he opened shop in N.Y.C. This is not a mass produced instrument and you are not working for a large manufacture! You work on a per job basis and every job is unique and if your customer does not feel that from you they will not return. What is scarey is how many of you are willing to stick your necks out there with a diagnosis based on one picture! Then the job comes in; it's more involved than what the picture shows but you have already quoted the job, but don't want to lose money so you get physical with someone property so you can get to next repair.Car Repair shops do not quote repairs that require diagnosis over the phone, The instrument is not in your hands; you know NOTHING about it! Corporation practices carry no weight in this debate. Corporations are not in business to handle situations on a personal level;you are!The hole is about to become a well!
Cars and guitars are both objects that are frequently repaired. So as far as that Venn diagram goes, they do meet in the same area.
As far as curriculum, you have been arguing passionately with some heavy weight repairman for a couple of days now. These guys are at the top of the craft. Maybe less famous than Frank Ford, Dan Erlewine, or Bryan Galloup, but certainly as talented and accomplished.
You have named some factories. They are small companies. They do repair work. Roger worked as a repairman before he started building. He married Irving Sloan's daughter. Look him up if you want to do some research on repair.
Outside of these small factories, the reality of producing tens of thousands of instruments sets in. That is where the things fall through the cracks and repairs are far more frequent. And those folks do not want to be in the repair business. Fender, Martin, Gibson, Ibanez, the list goes on and on. They all have factory authorized repair programs because they do not want to deal with it themselves. Many of the people who have been posting sentiments that are in conflict with your own either hold these authorizations or have in the past.
Using exceptions does not prove a rule. However, they are frequently used by the uninformed to bolster weak arguments.
As far as long distance diagnosis goes, that is what is done here. While certainly not foolproof, many folks have learned a great deal on this forum. Probably saved some money, too. However, for a local customer, every pro on this board would examine the instrument before quoting a repair. But since this is the internet they do what they can to help. This particular repair is common. The diagnosis is simple. So is the remedy.
There was a time when a car could be fixed without hooking it up to a computer. The computer makes diagnosis quicker. It does not make the repair better. And when you have a flat tire you do not need a computer to diagnose the problem. Tire flat. Change tire. This repair is a flat tire.
Every pro here has qualified their answer by saying they work from the obvious to the more complex. That is how repair work is done. Somehow, that does not seem to quell your fears. That shows an incredible lack of understanding of the craft. There is nothing more to be done.