I truly think he has reached or nearly reached a psychological limit of recognizing the lack of talent on offense, and to some extent the team all together.
It's like having a group project and everyone else is a knuckle dragging mouth breather, and you have to decide whether or not you are going to step up and try to get everything done yourself, or you're gonna let everyone else bring you down. And sometimes, the project is just too complex and too involved to be able to do all on your own, no matter how good you are.
I don't think it's reasonable at all to expect Josh to be playing his best football or even maybe close to his best football when there is just such a heavy weight of futility around everything. Something has to change and it has to change fast.