People have short memories though , have we forgotten that before he came to Arsenal, Ozil was playing at a world class level for 3 seasons straight. He has begun showing glimpses of his quality, just needs to step it up a bit more and be consistent. Ability wise he's up there with the best attacking midfielders imo.
Also its like Osman said, Cazorla had a better season, but he is not on the same level as Mesut ability wise.