Good posts, but you guys leave out the most important point, which is not so much the cost of the object as the claims to sound quality.
In other words, anyone should be free to spend, say, $8,000 on a couple of Ethernet cables if they wish. It’s still a free country, after all, for the most part.
Maybe their kids will put them under conservatorship if they find out, but that’s ok.
The problem starts when some of these people come on here and start making grandiose, absurd claims of HUGE sonic improvements due to the Audiophile CAT-6 cables.
Worse, when highly educated folks with careers in computer science-related fields make polite attempts to gently educate them as to why that’s just not possible, these people get all hissy and start assailing the so-called "naysayers" with charges of subpar hearing; mediocre, non-resolving systems; and more generally blinkered ignorance of "science" that conveniently has yet to be discovered.
Calling these people "idiots" is both hyperbolic and medically incorrect. Most of them seem to possess average intelligence; and, in reality, the reasons why they propagate false claims and sow division are far more complex than just idiocy, but that’s another conversation.
Suffice it to say that we should probably refrain from just calling them idiots. We can, and should, be more inclusive than that.