Yes, if your player does not shoot the PPS rating will be zero. However, I don't think it is at all influenced by his performance.
My opinion is this. Every time your player shoots, it serves as another piece of information used in the PP 100 shot average. This makes sense because if he takes an outside shot the chances of it going in could be much different than if he takes an inside shot.
So - if your guy does not shoot, there is no input to the formula. Therefore, nothing can be reported.
Run of the Mill Canadian Manager