Hi Paul,
I think I can imagine what you think is in music "healthy". And yes I personally always found Bach extremly healthy if not of vital necessity for keep once musical reason clean. And the serene modest musical passion and clear architecture of great classical composers are for me always like coming home in the fielld of pure musical nature.
But.... I do absolutly not feel the same with music from composers of the 20th and 21th century who are simply imitate that certain language of one or another earlier musical epoque (like barowue or classical). I always felt there was kind of untruthfulness, as far they just imitate one single step in musical history and avoid to develop their own kind of musical expression out of their own (musical) reality.
Thanks god we have no more Pricipalities of Bach or Mozarts time where the question if music have a chance depends on the question how musical sensible one single sovereign is. And yes not everything which iis part of our musical reality must necessarily be part of what we ourselve do really want to express.
I understand and accept, that that the sens of overthrow you feel in for instance the music of Schoenberg and his pupils is not what you feel any necessity for in your musical intentions. And yes it is absolutly wrong to make Schoenbergs composition concepts to kind of an academic standard of how 20th century music has to be written.
But on the other side their ntention was imho just part of the 20th century as a whole: keeping the musical thinking on an equal intellectual abstract level which made by far the most innovations in science and technology of the 20th century possible. It is a thinking which has to be ready to build up completly new concepts, which does not fearfully stick on a few familiar conventions, but is ready to try everything based on completly new assumptions, Exploring the realm of what hitherto has always been the "dark side" since that is the area, where new light might allow new discoveries.
If music is a language, than the language does "not only" rely on unchangable physical laws, but also on the Ideas which want to be communicated in that language. Given that no one can pretend to know any absolute truth or "better" Truth, than others we must admit, that even musical experiments and explorations for instance of the early 20 th century do have their own truth to tell. Which is as you underlined rightly today nothing else than one step in the ongoing path of our musical history. With not more but also not less impotants as Bach and Beethoven may have had for Wagner, Schumann fo Alban Berg or Liszt for Debussy and Debussy for Cage or Ligeti.
If music is a language to exprress what human minds and human creativity is able to, it is imho very "healthy" to listen to and try to undestand, what others have already told in their own time with their own means. If you just deny to understand what has happend in music the last 150 years I fear you might end up like an musical Kaspar Hauser.
And guess what It was exactly Schoenberg and his Pupils which took that commitment to understand und study the musical tradition as deep and severe as possible (Just take a look on the incredible amount of most ambitous conventional compositions and Counterpoint-Studies of the young Alan Berg - of which I have recorded many for the very first time) for instance and you will see, that their main Intention was definitly not to destroy any tradition, but moreover to carry it on to build up upon it. You can also see this aspect in the strong commitment of most early dodecaphonic compositions of the 2. Viennese School to classical form-Concepts like Suite, Sonata, Variation etc. (Which I admit makes it still very attractive for scholars and academics to analyse and teach)
But: To know and understand what our musical tradition is does not answer at all the question, what our answer might be.
And here it depends on our decision what we would like to realise, what we are fascinatedd from, what we feel the need to express. A reasonable composer today would not feel compelled to write music in dodekaphonic style, because any of his academic teachers told him this makes the top of his curriculum.
He would just listen to what ever meaningful music he can find and would sooner or later feel exactly what he wants to answer. And it is my humble opinion, that the more he is able to understand what the great musicians of the last centuries have done, the deeper his answer might be. That is whay I would be very careful to exclude half of our musical history even if this as you rightly pointed out is all already not more and not less than our musical history which when you understand it well may at least lay the foundations for what we can do in the presence we are living in.