I think atheists can't grasp what kind of being God is to Christians and other monotheists. Why would the most powerful being, who created reality, the stars, and every single living creature, be bound to human moral standards? To an eternal, all powerful, all knowing being, we are lesser than ants. He can do whatever he wants, he is the absolute master of everything that exists.
Ironically, when people make these sorts of moral judgements against God they are using the very same Christian moral framework where you have to be meek, humble and kind to everyone, no matter your post or status in life.