I think many peoples' issue with Facebook is that they have proven themselves to be untrustworthy on numerous occassions. They're constantly moving the goal post on user privacy with and without consent and they don't treat business users much better.

It's not surprising that people who care personally about Oculus would not be happy with the Facebook acquisition. Especially since the gaming community has a very strong aversion to the toxic social gaming landscape that Facebook was/is host to.