Facebook has a problem in that it seems to frown on "intelligent" content. Long form journalism, in depth analysis, professional content (industry journals, tech blogs etc.), none of this content really exists on facebook.
I have friends that read hackernews, we find similar articles from hn interesting. But I would never think of sharing one on facebook, and I would be surprised if a friend of mine did so. For some reason, facebook is just not the place where content like this is shared.
This is the advertising proposition of non-facebook media.