Ask HN: Why hasn't Facebook added RSS?

If I were Facebook, I would add an RSS section to the site. People already use Facebook, but adding RSS would give them more information on what sites I value. Furthermore, it would make it easier for me to share the articles that I value through its site. Although as a user I might be leery of using Facebook for RSS, there would be a lot of benefit for Facebook and the users. Side benefit, with facebook buttons on practically every site - it would be trivial to add a subscribe button and then it would auto-populate the RSS into users accounts.