I think it's only partially Gordon's fault. I have been watching pretty close how they have used him. He is basically either a decoy or they park him on the 3 point line the vast majority of the time. Gordon's game used to be a bunch of driving and mid-range shots. That isn't even in the regular playbook with Vogel for him. If Gordon isn't hitting deep 3's he is pretty much useless on the court. Vogel is a huge reason for his ineffectiveness although Gordon's lack of aggressiveness is a factor too.