cryoburner,
I agree with everything you said. Audio is so extremely subjective, and many enthusiasts are insecure and/or not very technically minded. Here's an example:
Machina Dynamica's Brilliant Pebbles "Brilliant Pebbles is a unique and comprehensive system for tuning the room and audio system based on special physical properties of highly symmetrical crystal structures." It's a bag of polished rocks for $60 and that firm has been in business for quite long while.
In audio, as for many things, more expensive is definitely not always better. There is on the other side, some reasonably prices gear that does quite well. bit_user mentioned Blue Jeans Cable and there's an example of a firm with good cost/performance engineering.
At the top end, there are some engineers that have designed cables that while outrageously expensive do produce results. I've heard some amazing Wilson Speakers- really incredible- and incredibly expensive. One memorable event was spending some time with Ray Kimber in 2006 when he demonstrated some prototype
Beryllium cables that he said would cost $80,000 retail- the whole system was about $200,000- and these cables had characteristics that were tuned to a discrete 4-CH digital recording configuration of his invention-
Iso-Mike- and that system was just astounding. It's based on very high phase coherence in the recording that is duplicated on playback. The listening position in effect duplicates the 4- microphone position. The imaging is palpably real. One of the recording I heard included audience applause and I could aurally place every person applauding on every side. I've never heard it's equal since, but that did depend on the recordings being played back on essentially the output of the recording device.
There is a lot of snake oil and placebo and the users have to delve into the technically to sort it out as well as refine their taste. Audio seems to me to be more far difficult by far to get right than computing and, so far, computing and audio are still not ideally combined.
Cheers,
BambiBoom