Facebook did the same thing they did with Instagram, they bought the company, kept it essentially independent with the founders continuing to run it as an independent management team. As with Instagram, Oculus is now big enough to actually matter to facebook, and so Mark proceeded to fuck with the successful management team until they quit. It's almost the perfect example of Facebook failing to innovate internally.

Isn't Oculus doing better than ever? Citation for "Mark proceeded to fuck with the successful management team until they quit"? (genuine question)