I think, on his day, Hemdani is a very good footballer. His form did drop suddenly in the 2nd half of last season though.
This season it has been clear that he is not in Walters plans. A players reaction to that can either be to work really hard in training, impress in reserve games and try and change the managers mind. Or a player can show little interest, accept that they won't play again and cheer themselves up with their bank balance. Hemdani, for whatever reason, chose the later. It is for this reason, and nothing to do with his ability as a footballer, than I won't be calling for his return.