You're mistaking observations of generational trends for denigration.
The fact that younger generations don't hear music performed by (acoustic) instruments as much as we did decades ago is just that - fact. How many youth regularly hear a french horn or piano played right in front of them? It's not their fault - it's just the way things have evolved.
The question presented is: what's hurting the "audio hobby." If the "audio hobby" includes high fidelity recreation of the sounds of musical instruments in real space, knowledge of those sounds is paramount. Younger folks don't seem to value that experience as much as previous generations - thus the decline of the "hobby."
Criticism of changing musical content is another matter - that's been going on for over a century and isn't likely to change.