In music THE truth is that pure Cmaj7 chord tones are C, E, G, and B. There most certainly are pure, irrefutable, without a shadow of a doubt, hard eternal truths. But, art and interpretation are broad. (again, the separation between academics and art.) There is no doubt whatsoever that the facts are the facts, and there is no doubt whatsoever that most bass players don't know them. This is why I am here!
Still, I liked your thinking! And I know a lot of people who agree with you! And I do as well in many points of philosophy!
Too bad the other thread is closed... I wanted to respond...
About what you wrote above... Cmaj7 is only C E G B in a 7 note diatonic scale system. If we had an 8 note system with the new note H, then C E G B would actually be a Cmaj8 chord.
(C D E F G H A B C)
(1 2 3 4 5 6 7 8 1)
Cmaj7= 1 3 5 7 = C E G A
Cmaj8 =1 3 5 8 =C E G B
(H = modern A) (A= modern Bb)
so Cmaj7 would sound like our modern C7
C6 would be C E G H
In the overtone series, between the fundamental and the 16th partial, there are 8 unique pitches (accepting octave equivalents as being the same note). Our musical ancestors chose to have a 7 note diatonic scale system to clean up the sound and avoid the semi-tone crunch that an 8 note system would have. This was done for aesthetic art reasons. A choice of Art.
So you can see that Cmaj7 is only C E G B once we accept human traditions based on art aesthetic, that has been practiced and then codified by academic methods, in order to preserve and pass down this art practice to succeeding generations.
The sound may be truth, but what we call it, and understand it as being is convention.
I'll chime in again later but the way I've heard music discussed in all the schools around here, is that the art comes first, the academic then condenses a lifetime of art creation in a manner that can be learned in months. As generations pass, 400 years of art can be learned in 4 years through academic means. Every generations revises their academic traditions to encapsulate the new art traditions of living memory.
In the other thread you mentioned that in order to speak French, you have to learn it first... yeah but in order to learn it, the language of French has to exist first. Language is created, and renewed through an art process spanning centuries. Academic practices ensure that a person can learn in 10 years something that took 500 years to create. They go together in a sort of "chicken and egg" process, but not really. When you get down to it, the art comes first. The art creates, the academic preserves. One can create without preserving, but one cannot preserve what is not yet created.
Again, I gotta go out now. I hope this thread is not closed by the time I get back. The threads on the BG side grow to quickly for me to keep up with....
I think one has to think beyond an individual lifespan to appreciate this most effectively.
take care...

I read this as saying an artistic choice had to be made about an academic concept (making the premise 'diatonic scale system' is academic), doesn't the academic need to exist prior to making a choice about it?