We do know, we've known since Unworthy. It's that he has all the traits to be worthy, particularly self sacrifice (which is why Jane could use it, because of her willingness to kill herself not just to save tons of lives as Thor but to also help much less people as Jane Foster, and it's why Bill could use it, since he let his people butcher him so he could protect them) and hasn't lost them, but he doesn't personally believe that he's worthy or should be using it because he's a God, so the doubt makes it so he can't. But he's on his way back by going back to being a hero and fighting the war, which is why he can lift the chip. It's about him developing a higher standard for his morality because of his doubts about Gods that he has to meet before he can be normal again. The hammer isn't cucking him, he's subconsciously cucking himself.