Does that distinction really matter? I use Atom/RSS interchangeably and from what I can tell there is very little difference for me.

We were talking about RFCs, so yes. It's the fundamental qualitative distinction between the two technologies: good specs really do matter.

https://pwn.ersh.io/notes/why_specs_matter/

https://www.xml.com/pub/a/2002/12/18/dive-into-xml.html

https://web.archive.org/web/2004/http://diveintomark.org/arc...

http://www.smashcompany.com/technology/rss-has-been-damaged-...