While you are totally right that our ears and brain are no where as sensitive as a high end mic setup there is PLENTY of things you cannot even wish to record. Beside, the limited ability of our useless brain won't form an accurate impression from graphs and numbers (or fancy words that doesn't mean anything on the non scientific spectrum). Therefore we strive for comparison from what we experienced already, it is a lot easier to relate something that you have first hand experience with to something similar.
Trying to record a pair of headphone with different setup will yield different result. Amping does affect the sound of a pair of headphones, even more so with a tube amp.
Expecting human to collect data without their needed tool is even more stupid. If you still think graphs tell you everything, you are missing out on the more human side of things in this hobby. Everyone hears differently, thanks to non perfect human body and mind.