> I seldom see any discussion of the underlying math, and instead see discussions of timbres, instruments, and stylistic/historical influences

Music today is utter crap at all levels, this is a verifiable scientific fact.

This is probably why.

Music "theory" was invented as a critical tool (i.e., basically to enable reviewers to describe and evaluate the music of the time), not as a composition tool.

Basically, we're holding it wrong and it's doing us harm.