The angle is to put the point out more without bending the wrist away from the strongest position.
The angle also let's the design incorporate the little finger guard on the spine which keeps the hand from sliding up on the blade. I'm not sure how much of an improvement the guard is in practice but it makes me less afraid of slicing my hand open.
I think Ban's Le Griffe Pikal does both of the same things better, the finger hole angles the blade in a similar way and the fact that your finger is going through the tang means the knife won't slip down but I think mine is more comfortable, penny loafers vs. combat boots...