It's a question of plausibility based on the greater simplicity of certain explanations. No, the existence of the unconscious side of the human mind doesn't prove necessarily that there's no divine judge or cosmic mind. But that's not the logic at work. The argument here is an appeal to the best explanation. I'm just saying that the theistic or mystical explanation starts to look redundant when we appreciate how the religious ideas may have arisen from the relation between our unconscious side and our personal self.