I have to admit, I felt a bit disappointed too. Carmack and Facebook always struck me as an antithetical pairing - the creativity/independence of the former didn't seem to sit right with the maniacal/emotional exploitation of the latter.
I think Carmack just doesn't give a flying f* about Facebook or etc. he is interested in tech and he clearly works on stuff he is passionate about. He worked on VR and not work for Facebook. Facebook just happened to be paying for it.
