In the early days of RSS, Dave Winer himself compared RSS to Usenet, so it's not a completely ignorant thing to say.
Except for the mailing list, RSS is the only relatively-heavily-used thing on the internet that shares Usenet's "openness" virtue: namely, there is no single "gatekeeper" organization that a reader must rely on to follow the authors in his RSS feed -- the sudden trouble that the OP experienced when upgrading to Mountain Lion is about the most disruptive thing that could happen to a reader's relationship with the authors in her RSS feed.
(If the assertion I was responding to had been that the designers of RSS should have tried harder to emulate Usenet's subtler virtues, I would have agreed.)