Why do intelligent people deny audio differences?


In my years of audiophilia I have crossed swords with my brother many times regarding that which is real, and not real, in terms of differeces heard and imagined.
He holds a Masters Degree in Education, self taught himself regarding computers, enough to become the MIS Director for a school system, and early in life actually self taught himself to arrange music, from existing compositions, yet he denys that any differece exists in the 'sound' of cables--to clarify, he denies that anyone can hear a difference in an ABX comparison.
Recently I mentioned that I was considering buying a new Lexicon, when a friend told me about the Exemplar, a tube modified Dennon CD player of the highest repute, video wise, which is arguably one of the finest sounding players around.
When I told him of this, here was his response:
"Happily I have never heard a CD player with "grainy sound" and, you know me, I would never buy anything that I felt might be potentially degraded by or at least made unnecessarily complex and unreliable by adding tubes."

Here is the rub, when cd players frist came out, I owned a store, and was a vinyl devotee, as that's all there was, and he saw digital as the panacea for great change; "It is perfect, it's simply a perfect transfer, ones and zero's there is no margin for error," or words to that effect.
When I heard the first digital, I was appalled by its sterility and what "I" call 'grainy' sound. Think of the difference in cd now versus circa 1984. He, as you can read above resists the notion that this is a possibility.
We are at constant loggerheads as to what is real and imagined, regarding audio, with him on the 'if it hasn't been measured, there's no difference', side of the equation.
Of course I exaggerate, but just the other day he said, and this is virtually a quote, "Amplifiers above about a thousand dollars don't have ANY qualitative sound differences." Of course at the time I had Halcro sitting in my living room and was properly offended and indignant.
Sibling rivalry? That is the obvious here, but this really 'rubs my rhubarb', as Jack Nicholson said in Batman.
Unless I am delusional, there are gargantual differences, good and bad, in audio gear. Yet he steadfastly sticks to his 'touch it, taste it, feel it' dogma.
Am I losing it or is he just hard headed, (more than me)?
What, other than, "I only buy it for myself," is the answer to people like this? (OR maybe US, me and you other audio sickies out there who spend thousands on minute differences?
Let's hear both sides, and let the mud slinging begin!
lrsky
Without your recent addition, I would not have found this thread. I just read it all. Most, here, go through a some similar experience/frustration attempting to share/turn on someone to the "sound". In the words of Yogi Berra, "There are some people who, if they don't already know, you can't tell them". Next time, I suggest you just pull a Tommy Smothers. Tell your brother, "Yeah, well mom always liked you best"! Smile to yourself and give him a hug.
There are all the same arguments in this thread-prove to me you can hear a difference, listeners are delusional, physics says there are no differences, charlatans are always eager to take people's money versus I like what I hear. I have two brothers who don't listen to music and who love golf. I gave up on golf years ago once I decided that I love hiking in the woods rather than trying to hitting a ball in to a hole on an irregular surface. We never talk about audio or golf when we are together.
I keep my audiophila habit a deep dark secret. Regular people think you're crazy or extravagant or both. Of course, these same people think it's fine and worthwhile to buy a Mercedes or BMW. I think people are influenced by the non-stop luxury car advertising.
there are two types of errors. failure tomhear what esists, and claimimg to hear what does not exist.

the problem:

in the empirical world the only corroboration is anecdotal, which is an opinion, i.e., it is probably true and probably false.

perceptions are hard to prove.

so, i would accept anyone's claim as to what is heard and consider it an opinion.

knowledge can not be attained in the empirical world. thus claims of differences cannot be certain, onl;y probabilistic.

the question of differences in the sound of cables is like trying to detrmine which of three versions of an accident witnessed by three people actually occurred.

there is no way to corooborate any account of an accident and no proof that what one hears actually exists.
Do you feel the need to convince him? Do you win in some way if you do? and what if no matter what you say, he won't admit it?