Singer didn't direct FC.
It seems to me Snyder faces the problem that Superman is not really a character insomuch as he is an idea. Most people know the rough outline of what became Superman's defining traits but nothing more than that. As such, there's absolutely no way to please everyone because Superman is such a personal, imaginary construct that no two person's impressions of him will be the same. Trying to present him as a perfect boy scout will infuriate people, trying to present him as flawed will infuriate people. It's a lose-lose situation.
Also WK, Miller is probably best known for his Daredevil work.