The big one is that he claims that Zuckerberg just ripped off his original code. He lost that one in court.

His opinions on Zuckerberg's personality are heavily flavored by that personal conflict.

Second, Facebook does not have a monopoly. Unfortunately for them, social networks are not that sticky. And they can only continue buying every up and coming social network for so long before they miss the critical one. (Perhaps Tik Tok will turn out to have been the one...)

And finally Facebook is not a Ponzi scheme. I think that they are overvalued. But not Ponzi.