I think DC's success with the Batman films clouded their judgement.

I think DC's success with the Batman films clouded their judgement. Unlike the Batman, Superman was never intended to be 'dark.' The folks over at DC took a winning equation and tried to apply it across the board and that's just never a good idea. Chevy and Ford don't market their cars the same as their trucks and DC shouldn't be shoe-horning one approach onto all their characters.
http://www.hollywoodreporter.com/heat-vision/batman-v-superman-fallout-producer-897071