How can a system be judged with highly processed, non acoustic music?

You are dead right...

People dont know that music is not physical  sound but  sounds recognized  and fully interprated to be "music"  by our brain...

Musical or voices timbre with the less processing possible  are the ONLY way to judge a system...

Most people judge gear in a non acoustically treated room, but each room  must be treated for each specific system anyway to be a valid environment and a fair one, able to translate the S.Q. potential of the gear in  "musical" recognizable voices and timbre instrument in this specific room ..

I just listen to the music I like to listen to and see if it sounds good.
I try not to overthink things.

I have come to enjoy Jay's thread and videos. This thread was inspired by my repeated request that he use acoustic, little processed content.
Even with his use of digital only, his high quality playback system will surely reveal significant and pronounced differences between components best with acoustic music. 

Jay's amplifier thread is all about evaluation/analysis.