I agree with you completely. I no longer pay any attention to the you-must-be-crazy-to-think-you-hear-differences-in-audio-cable crowd. BUT, I suspect that there are three factors that figure into this:
The biggest one is:
1) They have little to NO experience with live, unamplified music as one would hear it in the symphony hall, the jazz clubs, or parades. This means they couldn’t tell a flute from a piccolo (or a clarinet for that matter), and therefore have no sense of the actual tonality of acoustic instruments. That will make evaluations difficult if they’re using KISS records, for example, to evaluate equipment, as very few rock records are well-recorded (Brothers In Arms, Trinity Sessions notwithstanding).
2) They don’t understand terms such as "low level detail" or "harmonics" or most of the vocabulary that was invented 30 years before they arrived on the planet, and so they invent the meanings of the terms, and then sneer at the established terms because none of their peers know any of this either.
3) Their systems - and the music they play - do not have the resolution level to hear the differences. (This was actually put forth by one of the Founding Fathers of High End Audio, Ivor Tiefenbrun, who said, ’If you haven’t heard it, you don’t have an opinion." His other comment, when told people could not hear the difference between his turntable and say, Ariston, "Then your equipment does not have the resolution to show you the differences." And he said this in the late 1970s, if my memory is correct.
AND, a fourth!
4) They have completely untrained ears. Training one’s ears is not hard, but it does require patience and discipline. I knew music LONG before I discovered audiophilia, and spent decades in symphony halls, jazz clubs, cello recitals (from friends who were teachers and demonstrating their pupil’s proficiency), but I wouldn’t have known how to integrate what I heard in the symphony hall with what I heard a piece of equipment was NOT doing (but SHOULD be doing) to something I KNEW was on the record. It took a year or so for me to "hear" how recorded music varies from live music. But I still had to train my ears. No way around that. And they haven’t. It’s that simple.
That seems to be asking too much of many posters who have zero experience with much of the high quality equipment (which, unfortunately, is also priced higher than they can spend), so they speculate. Now, my mother DRILLED into me when I was young, that if I didn’t know about a subject, I should keep my mouth shut. That no longer seems to matter to the unknowledgeable - on ANY subject.
Hence, people on forums who want to tell me - someone who can read, write and play music (none of them great, but still...) - that I must be hearing things to think I can hear the resonating cavity of a nylon guitar, or that I cannot hear the tape splice in The Nutcracker Suite (Mercury Living Presence). I just mentally realize they don’t have the tools (equipment, experience with live music, and trained ears) to "get" what I’m hearing. You cannot SPEAK knowledge into someone. Anyone with children knows this (and some of the responses on here remind me of 14 year olds with their ’nyah-nyah-nyah-nyah-nyah’ responses), otherwise, none of us would have burned our finger on the stove even though grandma had said, ’don’t touch the stove. You’ll get burned.’ Same thing with sharing insight or knowledge. It can’t be "transferred." It can only be experienced.
If people want to remain unknowledgeable and ignorant, I say, LET ’EM. It’s no skin off my nose if they like being that way. Anytime someone sneers before even asking ONE question, they’re not interested in learning. They’ve had a bad day, and they came to a forum to discharge their anxiety/fear whatever. They write their dismissive response and get a temporary fix of "GOTCHA" but it goes away after 10 minutes, so they return and spend none of their time learning, and all of their time bitching. Why fight with some complete stranger over what they don’t even know? Waste of time! You’ll drive yourself crazy.