Why is science just a starting point and not an end point?

What makes you think your claim is true?

Perhaps you can provide examples that I've obviously missed. As I stated, test tones and sub audible measurements are no indication of how music sounds.

Science asks the questions that humans contrive with the tools humans design. Data is selected according to human interests. Worshipping tools rather than contextualizing their use is an instance of misplaced concreteness. A.k.a., "scientism."

Science records, stores, reproduces and delivers music to your ears. How it sounds is user defined. 

Test tones are a good indication if your component is capable of delivering the musical signal in its entirety so you can decide how it sounds. 

Holy crap! This should be easy. Why am I not surprised nobody gets it???! 

Why is science just a starting point and not an end point? 

Because science is a METHOD not a RESULT!  

Science properly understood does not fail at all. That is like saying Newton "failed" because he didn't know what happens at relativistic velocities around black holes. Science is the method that helped us discover and understand both Newtonian and Einsteinian physics.  

The fact we can reliably hear things we cannot reliably measure is no failure of science. The fact so many lack a firm grasp on what science even means indicates what has truly failed is our system of public education. Now there we have a genuine and profound total fail.