That philosophy applies to the $10 old Sony RTR you find at a yard sale.
However, it does not make sense to me to buy a non-working SOTA tape deck and just "sort of get it working" by fixing it yourself. What's the point of that unless you just want bragging rights?
Remember that I have seen hundreds of tapes decks that have been "worked on" by owners. It's not a pretty picture. Often, the unit ends up having more problems than when they started. The Baxa post is a perfect example: someone thought they had a bad capstan motor, so they took it apart, couldn't find or fix the problem and they put it back together with a bunch of critical parts missing.
My view is the contrary, spending time and resources in a $10 old Sony is a poor deal, refurbishing an old Studer A80 can be a challenging and entertaining hobby. I agree with your view of the average situation and will avoid focusing on specific cases of our members, but will object that the Studer A80 is a perfect machine for someone wanting to learn. A decade ago I was not aware of the existence of the Studer A80, today I can identify what is the guilty rolling part of my Studer just looking at the wow and flutter spectra with adequate resolution.
For reasons that many tape hobbyist already know - available complete service manuals, standard wearing parts and non critical availability of any electronic spare, plenty of support in archived and current forums, I think that the A80 is a good approach to reel to reel DIY enthusiasts, particularly if we manage to get one for a decent price
- when I got my machines prices were around euro 600 for a complete, no missing parts, but not serviced machine.