I don't even know that that's true, I work in IT and it seems to me more and more people don't bother learning how something works or the principles as to why and just take the "book answer" as how to fix the problem which is usually also wrong. Learning how and why something operates is the key to understanding how to correct it. I don't think its necessarily the service dept looking for cheap labor as much as it is the people being hired took shortcuts in their education. In IT, we call them, paper certified admins because in a production environment, they cant fix anything that doesn't occur like it did in the "book/test".
There's plenty of "brain dump" test answer sites on the internet and for almost every occupation, a dealer targeting these types on employees will only end up paying labor 2-3x's which ends up costing them money so I don't think that's it, there's just
choices in the labor force.
I took my truck to the dealer for an alignment, they gave it back to me aligned but with the steering wheel 15° off center to the right (it was previously straight). They re-did it 3 times (4 hours) and the service advisor told me that I couldn't be pleased and that was they best they could do, I told him no, go get your shop foreman. The shop foreman came and said he'd take a look and didn't make it 100' and came back saying it wasn't right and that he'd put his best suspension guy on it.
Literally 5 min later the shop foreman brought the truck back driving perfectly and said he was going to have a talk with the other alignment guy, about that time the service writer walked up and the shop foremen said I want to speak with you about this job.
I doubt that shop was ok hiring a bad tech and tying the alignment rack up for 4 hours then having to place another tech on the job.
Foreman came back to talk to me before I left and said he wasn't paying the 1st tech for the job and was going to pay the 2nd that fixed it. Foreman was a car guy and we got to talking about cars and he expressed his frustration with the labor force