That is a very strong point I had not considered. Facebook does not have a smooth relationship with developers. Oculus requires involvement from the developers in order to further develop their product. I reason the Facebook culture of move fast-break things (but don't document it too well) might hurt Oculus.

Plus, I saw Oculus as a technology to build upon. I was already planning to use it with robotics. Now, its merely a pawn in Facebook's game.