Lets say I can convince all of my friends to download and continually sync their FB data. Then, I build a desktop app or web service on top of an open, distributed network with a UI that encompasses most of the features that people use on FB.

It seems like I could interact with my friends, still use facebook as I please, and gradually evolve my social media interactions towards a more open, distributed network.

Any reason why we would not see a handful of such projects emerge?