Note that the guys at Oculus either are not interested anymore and just want to cash out, either actually needed more support (wish is extremely doubtful given what they already got), or lacked the entrepreneurial mindset to not be bitches and get that two billion the hard way.
People never would have backed a project on Kickstarter if it said "Hello this is Facebook we want to make VR goggles give us money", that's a fact.