@auntiesuebee I think it's because with the others you mentioned, people understand what they are being offered and most don't require any technical knowledge. With mechanical repair techs, most don't have enough knowledge about the item and have to trust the repair person. We all know there are shady techs out there in all of these professions. I have seen some first hand. Like any profession, most are honest and trying to do what is right and best overall, but the bad apples get more attention.
In the early mid eighty's, I saw a note to put 4 coil springs on an early 70's Dodge Magnum. The problem? Torsion bars on front and leaf springs on rear. This was to a co-worker at an auto repair shop that had taken it to a different one for a battery problem because it was under warrantee there.
Bottom line is I think it is simply a level of understanding and required trust issue.
In the early mid eighty's, I saw a note to put 4 coil springs on an early 70's Dodge Magnum. The problem? Torsion bars on front and leaf springs on rear. This was to a co-worker at an auto repair shop that had taken it to a different one for a battery problem because it was under warrantee there.
Bottom line is I think it is simply a level of understanding and required trust issue.