Well I wouldn't exactly agree on him thinking Steem is a large threat to Facebook. Centralized or not, Facebook still has the largest base of users on any social media platform. Currently with the average daily users on Steem, we would have no way in competing. Also, I think Steem is leaning more towards a 'replacement' to Reddit as opposed to Facebook. Personally, I think Facebook is so big that nothing can really replace it. It's become too large of a business and advertising hub. My two cents.