To be fair, I think what we hear can indeed be measurable. It's the interpretation of the data, and relevance/applicability with our own unique HRTF's that is one of the major missing links.

Similar to how I would buy a pair of shoes, it would be nice if I could pop in a few measurements of my ears and head, and be able to spit out results that tell me what kind of headphones or speakers I might like. Just like a pair of shoes though, you still need to "wallk a mile" in them to really determine how well they "fit" you, but it would be much less haphazard and aimless. Perhaps one day.

The main issue I have with a lot of the hubbub is the stance that "all of audio is a solved problem" because of our current body of measurements, which I vehemently disagree. And throwing out subjective discussions entirely, because we cannot reliably correlate it with the data, is definitely the wrong way to go about furthering our overall understanding if we want to have any hope in achieving the above hypothetical future.