Another way to phrase this is, if only those who have achieved an uncommon competence can hear something, then one must conclude that it is also imperceptible to the common.
Regardless, people are always free to listen to whatever they want. IMHO, any criticism in this thread is directed at the audio industry that promotes "hi rez" music formats as "amazingly wonderful", yet maybe, as admitted here, only uncommonly competent people can actually hear a difference.
Regardless of the audibility of such "hi rez" files, what really gets to me is the dishonesty. There are a lot of "hi rez" music files out there marketed as uber audiophile which are either sourced from analog tape or just a CD quality digital file that's been upconverted and then sold as a hi rez file. Not to mention the remastering that often goes on so that no kidding, the hi rez sample will sound different, but that's not due to the resolution of the transport medium. I know if I were hawking online hi rez and CD quality music I'd make sure the hi rez one was about a third to a half a db hotter than the CD quality one so it would sound better in one on one comparisons with no level matching. It's not dishonesty, it's marketing!