His bio is about the same length as the Hokage's. 

Just sayin'.

There's that, and bio was never a required field in the first place. 
Though he is a fairly strong Genin in my opinion. I don't think there should be an A-Rank Genin. That's a little bit uber. Truthfully, there shouldn't really even be a B-Rank Genin, but most of the B-Rank Genin are Jinchuriki so I guess that explains that.