I think he's right about the lack of ideas. At the big two at least. But while his criticism has merit, who wants to spend time listening to it when it is increasingly delivered wrapped in ego and petulance?
Also I think it's a little disingenuous to talk about originality given that he has repeatedly used other people's characters as the basis of his work.
That's interesting data about how much of the direct sales market is made up of his work. Twenty percent sounds high although given the sales of Watchmen alone not unrealistic.