i agree that punk is a culture, as is hardcore, etc. I disagree that there's an undeniable sound associated with it. I could show you 50 punk bands you never heard of who if I asked you what kind of music it was, you'd call it metal.
As far as the jazz sound you speak of, yes I agree that this exists- however the point was that horns, upright bass, off-beat rhythms, 9th chords, etc. do not constitute this sound. I think the term is often misused (example: motw) and I'm not saying it was misused in regards to Ephel Duath. This thread just reminded me of that article.
I'm not making any assessments over this Ephel Duath record, just in general.