If neutral system could be really defined we could hire people with best hearing ability (conductors, musicians etc) to rate systems or pick them for us.
Isn't that what part of what these talented people do? They have the know how to create music we like - sounds we like - musical arrangements that fit together beautifully. Some experts are in heavy demand for mastering for the sound quality they create. Others provide key artistic input during the production. Whilst some have great skill in getting the microphones setup perfectly (and to know by ear immediately what is wrong when it ain't right)
I believe there is such thing as great sound or excellent equipment and that this can be measured and rated by experts. (Dr. Floyd Toole spent years researching people's perceptions of sound quality and found that we are not so completely different - but I grant you that there are many here who at extremes of the bell curve, as one might expect from obsessive behaviour about sound rather than "music", which Newbee pointed out so well)

