This is probably what's leading to my confusion too. My understanding of the term comes from the Dusty Groove / collector culture of the mid 90s. "Everybody loves the sunshine" as well as late-70s jazz-funk LPs with dark sounding tracks, were the essence of "rare groove". Even if the LPs were not that rare. if the scene as it happened in the UK had a different sound, that's partly why I'm confused.
I still need to read everyone's responses and think about them in detail to follow up, I still don't have a good grip on all the scenes out there, their history, and how they interacted. Thanks to everyone who responded so far.