Any time Snyder gets full control of a film (directs, writes and produces), it’s a recipe for disaster, Watchmen was decent because he just directed it, and used the comic book as the storyboard for the filming, 300 again was just the right place, right time kind of movies, so he got away with the way that was done and Man of Steel again was him just directing.
The movies he’s had full control, well Sucker Punch, Army of the Dead and now Rebel Moon, he just doesn’t do well when he writes movies he directs!