Fewer parishes seem to venture out of a very safe repertoire.
Your ideas on seasonal music are outstanding. Even parishes without a music director should be emphasizing seasonal hymns, songs, and chants. After getting a music ministry in gear with psalmody and a consistent set of acclamations, that should be a priority. Your musings on the purpose of hymnody is interesting, Not being a musicologist, I will not presume to debate your experience and logic. Lastly, a hopeful story.