The premise of it seems to be "he's got personality but no substance". Which is utter BS. To see where this author's coming from, you need only look at his go-to authority in support of this proposition:

Maybe, Mr. Smith, real estate executives and their banker friends and their fellow financial overlords and technocratic toadies aren't going to be the epicenter of every discussion about how to allocate the city's resources anymore. Maybe that's what Mayor De Blasio will stand for. Maybe New York will finally become interesting again, able to support a diverse community again, rather than the bland, gilded shell of its former self that it's become under decades Giuliani and Bloomberg. Maybe?

(Even the cover is framed in a way that's subtly mocking: oh look, they're like a sitcom family. "Their holiday card is going to be great. Then what?" Feh.)