Facebook is a long way from becoming a ghost town, it's just currently more like a superhighway littered with billboards. We'd really like it to be a cosy cafe where we could enjoy a cup of coffee and conversation with a friend or to.
Facebook is struggling. We are struggling to figure out how to work with Facebook. Until something else shows up en masse, you'd better get your Facebook house in order. Even if Facebook itself continues to mess up, fall down, invade your privacy, make unannounced changes to services... Even after all that, YOU HAVE GOT TO DEAL WITH FACEBOOK.
A swift and agressive Facebook departure might not signal the end of the dot com bubble v 2.o, but the beginning of real growth and real potential to do it better. And you know the tech teams at Google+ and Pinterest are watching the current stock crisis and legal morass with hungry eyes.