So; about the first film. Much of what i gather from it matches what others have said. The low-key tone and attention to powers suits the film. Singer was dealing with a film that should have had a bigger budget but didn't. Instead of giving up he probably said to himself... "they want me to make an action movie featuring a diverse group of heroes with superpowers, but they are constantly cutting corners of an already tight budget so screw them! I'm going to make a character story, with some action thrown in. And not just perfunctory action.' He knew that his action scenes could never really live up to fans' expectations with the film's budget so he went down fighting and made the best film he could.