Because it's a fantasy. Our ears suck. Don't trust them. Our brains lie to us. Don't trust it.The idea is to measure how often people (in general, large groups of people, not individuals) use subjective terms in relation to specific objective measurements, so that when someone can't or won't refer to measurements, (which is very often, as you know) we could still make a probabilistic / educated guess as to what they actually heard.
What's the problem with that?
It's a gigantic waste of time. Trust meaurements. Buy reasonably priced gear that measures well. Then sit at home and write all the flowery love poems to your gear that you want, but please don't share them.