It's strange because I love reading and looking at content other people post. Facebook is my favorite social media to casually peruse, but for some reason, I just don't really like contributing to it. And I think many of my friends feel the same way.
My unofficial, purely conjectural reasoning for this is that A) we are lazy. Posting pictures and statuses to Facebook takes quite a bit of thought and work. It requires the skills of a writer and editor, lest you look stupid or silly in the eyes of 1,000 close friends. And B) I'd argue that Facebook feeds are becoming platforms for click bate articles, serious news discussions and political conversations.
Scrolling through my newsfeed, there's an announcement about a concert, an article a friend linked about police guns that can now spy inside people's homes and one about current events at Duke and UNC distracting students from their education.
Facebook isn't for posts like "got new glasses!! yay:)," which I wrote on November, 11 2009 as a sophomore in high school.
People are turning to social media, specifically Facebook, increasingly to learn something new--not to post about a new pair of totally rockin' spectacles.
In a way, maybe social media is becoming less social.