I think the difference is that the Microsoft and Sony accounts are only used for authentication/account purposes. Facebook accounts are for much more than ensuring you have access to a game or Office, etc. plus, as others have said — you can have different Microsoft/Sony accounts. So you can split your professional and personal lives. This isn’t possible with Facebook.

The Facebook/oculus situation would be like if Microsoft required you to use a LinkedIn account to play the newest version of Halo. That would be equally strange.