The reality - objective reality - that I perceive is that for some reason - non measurable - some stereo kit just sounds really inviting - warm (now measure warmth)
Less treble is easy to listen to, have a look at treble roll-off, see if it correlates to inviting and warm. Or maybe you're a bass-head?
Probably much the way some musical genres simply sound better than others. I like some 70's pop - and Rachmaninoff - Second Symphony in particular.
I prefer Elliphant to Rachmaninoff (particularly Purple Light).
And Saint Saen (organ symphony) and Debussy (la mer) and Philip Glass. Those tunes may leave others completely cold - fine - but try and measure something objective about them. Impossible.
Bung 'em in Audacity, lots of objective things to see.
Thousands of tunes light me up - and tens of thousands of offerings leave me cold. So how can that be measured?
This is an audio forum, probably better asked in a brain measuring forum? I think there'll still be wide agreement that Elliphant is better than Philip Glass, though (particularly North Star).
many digital releases - particularly early ones - are simply unlistenable
That's because initially, in some cases, they mistakenly used vinyl masters, which have rolled off bass and boosted mids (to save space and avoid distortion on LP's). Because CD players don't then apply a corrective signal (no need since better at storing audio than vinyl) they sounded crap. Not a fault of CD technology, just the tinkered with masters that were used, which were necessary for vinyl.
So now you are left with only one thing - declaring myself deaf and possessed of no taste. About what I would expect in any kind of argument with a stereo zealot - no matter their particular religious bent.
You have a preference for a particular measurable characteristic, nothing wrong with that, just a case of identifying what is. Happy listening!