I enjoy reading your observations, very well thought through. Your points go mainly to tonality, which I completely agree is so subjective that arguing about it is akin to arguing over politics, art or religion. It's heckuva fun though!I've been contemplating whether or not to comment on this however we are in a philosophical discussion thread and this is fundamentally a philosophical topic (and an interesting & fruitful one at that) so I'll do my best to address it respectfully.
I often draw connections between the experience of listening to music & gear and that of eating food-- both are forms of sensory indulgence and both tend to elicit emotional connections & reactions (often strong ones) from people. People experience music as it is presented through gear and they experience food as it is presented through a chef or a cook. Just as a chef can prepare and flavor food to make it appetizing and beautiful to people so can a piece of gear color or tweak music so that it elicits a greater or lesser degree of analytic or emotional character. True neutrality I suspect would sound very similar to everyone's ears and while some people do seek after this type of signature as @blotmouse rightly observed the other day it seems like it might be the sonic equivalent of a rice cake. As such most people I think prefer to have some sort of coloration-- even minor-- in their sound. This forms the basis of everyone's differing tastes as not only do different forms of music benefit from distinct types of tuning and coloration, but everyone has different sensitivities, rooted in both innate and learned factors, that influence how they hear and perceive things.
While there are many different, probably limitless, tuning profiles out there one of the most significant areas of contention I notice stems from how people like their mid-bass & upper mids. Some people prefer more forwardness in the upper mids and readily write off even a minor mid-bass emphasis as "muddy". Alternately there are a good number of very well regarded IEMs out there that for me are way overloaded in the upper mids and weak in the mid-bass. In fact this is so prevalent that it's generally the first thing I look for in graphs & impressions when I'm trying to figure out if an IEM will be for me or not. I often colloquially refer to these different tuning profiles as, respectively, "Eastern" & "Western". This is because much music popular in Asia seems to benefit from tuning that is skewed more towards the upper mids and the sort of music that, as you say, I was raised on tends to benefit more from a tuning skew towards lower mids and mid-bass. I use the terms "Eastern" & "Western" loosely though as this is by no means an absolute rule and I know there are people all over the world who prefer both kinds of tuning-- often with the same types of music. Just as everyone's perception of and sensitivity to how spicy a dish is will vary to some degree according to what they are used to so is it true imho that, in the realm of sound, people's perception of what is tolerable/fatiguing/ideal etc. will vary according to what they listen to and what they are used to. While I agree that simply saying "East" vs. "West" vastly and inaccurately simplifies the matter there is imho just enough positive correlation to make the the latent distinction it is aiming for interesting and important to take into account when trying to understand where someone might be coming from when communicating heir preferences and/or describing what they hear.
Indeed and many are after a more analytic or intellectual experience-- neither is right nor wrong they're just two different approaches.
What's less defensible for me is when someone misrepresents factors that are more or less universal, or at least can be 'graded' fairly accurately by anyone doing a proper AB or even blind test. Stuff like resolution, speed, clarity, imaging. We all hear differently, but not enough that the differences will markedly change how we perceive these technical elements.
Tonality, timbre, tonal balance...that's the wild west.