He's probably tired, he's 20 and he never played an 82-game season before. Plus, he played in the summer for the Olympic team. He's probably hitting the sophomore wall (I made that up

44% is not that bad, and still is better than Kobe (

most of the players play good for a couple games and then they just suck. Nobody can play at a high level all the time, nobody's perfect.
The hype came for his athletic and dunking ability. I guess you all know who he was compared to. But he played better than expected as a rookie, so he got more and more hyped. I don't think that's nothing.