Rss seems like it's a pretty bad standard that doesn't let you do a ton with it and doesn't solve problems of things like discoverability or your ability to post content.
It's great for reading from lots of new sites at the same time, but it's clear that it hasn't taken off and when that happens it's normally for pretty good reason
Think they are referring to way it works, not technical details of implementation, as it isn't really "social network" with no ability to have any social action
As in you can subscribe to who you want and no moderator will stop you and then you can... just comment on a blogpost or article, with no 3rd party aside from this particular space moderators
It's great for reading from lots of new sites at the same time, but it's clear that it hasn't taken off and when that happens it's normally for pretty good reason