Napoleon Bonaparte was the greatest leader of his time. Why is he reviled so much?

I want to know why Napoleon is reviled so much. He is a great leader and a brilliant military tactician. His greatest flaws were his ego and his inability to accept that the world had moved on. I know he was power mad, but so was Washington. He had big plans for Europe and wanted to be a great leader. I can't find much of anything about his personal life, and I don't care much about it. I want to know what he did that made the world hate him so much. He lost his wars, but he won battles. That doesn't make him a villain.