I liked your end rant - what they didn't tell you in school - and I generally concur. For better or worse, I generally do things differently than the way students are taught in other classes, an approach that is perhaps more likely to cause trouble, but sometimes yields an interesting new sound or a possible solution to a nagging problem. That said, there was one point you touched on that I felt could be its own article. I also wanted to point out where I particularly connected.
RE: Blaming the Musician for not having the right sound, until you find the ability to always get the right sound for any musician.
Man is that a mouthful! You might subtitle this any number of ways like "Luck favors the over prepared," or, "Luck is what happens when preparation meets opportunity," or maybe "DIY sonic insurance policy." From my engineering experience, having spares/ backups / alternatives:
guitar amp (tweaked, see note-1 below)
setting up more mics than the song requires (see note-2 below)
Bass and Bass Amp (Note-3)
Snare drums, parts and a drum key,
picks, sticks and brushes
box of adapters
My biggest beef with guitarists is that they often don't truly listen to the tone coming out of the speaker and that generally, they over-push the amp - and / or the pedals - to distortion extremes that don't necessarily translate UNLESS you have the luxury of micing the room and not the amp itself. Having a DI helps so you can 'stealth process' after the fact, similar to the amount of Auto-Tune or drum editing you don't take credit for...
I like minimalist recording setups WHEN everyone is comfortable enough with the amount of leakage that may result and WHEN everyone is willing to take a chance with me. On the plus side, you have a better chance of knowing what each mic sounds like. The other option is over-micing, which requires that you pay more attention to each mic AND have the psychological willpower to only use the number of mics necessary (after the fact), both of which are harder. Since each song is a 'unique individual,' it is sometimes difficult to see far enough into the future to know how the song with develop / grow into itself.
No matter whether in a recording or live environment, I often find bass players push the low end too much. This poses a challenge in most smaller, under-treated 'studio' environments - where the bass leaks into everything - as well as at a live gig, where the resulting bass in the house turns into mush. A little science goes a long way to resolving the issue. Of course, like many solutions, you have to take the time to prove your point by letting the musicians hear the difference.
Getting the cab off the floor and at ear level reduces the 'boundary boost,' focusing the sound at the player. Then, close micing the cab delivers a proximity bass boost that allow you to reduce bass at the cab by a similar amount. This improves the bass tone in the house, reduces leakage and mud in the studio all of which clarifies the bass presence in the mix.
People Skills are more important than technical skills: Agreed! It was the hardest lesson I had to learn. Being a geek, learning social skills comes with the territory...
Computer Maintenance vs repairing audio gear: While true, the latter is particularly useful when challenging guitar amps are encountered, as-in, learning why amps sound bad or good from the inside out.
RE: Natural vs Processed
There is no one size fits all - you might get into a groove with certain set-up parameters UNTIL one situation where nothing works forces you to start from scratch.