No wonder the space program has stalled! Your friend's memory has failed him, usenet bears no resemblance to rss in anyway. Usenet was a discussion forum, rss is link syndication.
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.)
I remember back the late 90's when these formats were being created (I was involved with cdf's inception) and while I'm sorry this woman has been disrupted with mountain lion's removal of rss from the mail app, I disagree with you on the claim that rss is anything like usenet. Rss is, like cdf, a content delivery format which is just a simple agreed upon set of XML tags for title, snippet and so on. If rss had discussion or comment capability, it might be reasonably compared to usenet, but rss has nothing in common with usenet as it stands, it's a one-way protocol, I subscribe, or I publish, there's no discussion, as there is with usenet. In that it's open, with no single gatekeeper, it is no different to http, but comparing rss to http would also be pointless.
