"Facebook is not a company of grass-roots tech enthusiasts. Facebook is not a game tech company," he said in a blog post titled, "Virtual Reality is Going to Change the World." "Facebook has a history of caring about building user numbers, and nothing but building user numbers. People have made games for Facebook platforms before, and while it worked great for a while, they were stuck in a very unfortunate position when Facebook eventually changed the platform to better fit the social experience they were trying to build."
He doesn't necessarily think what Facebook has planned for the Rift - he postulates that it'll be social interactions like virtual face to face chat, virtual meetings and conferences - is bad or won't be beneficial to society, but he and his company want to focus on games and he doesn't think that's a direction the new Facebook owned Oculus will push.
He did however take the opportunity to plug the Minecrift mod that allows you to play Minecraft iin the current Oculus Rift devkit. Click here if you want to try it out.