True but Superman's character has been explored ALOT in film and moreso TV over the last 30 years but we havent seen him fight the big sci-fi villians on the big screen. I think that's what an audience has been crying out since the technology of the Matrix films teased what we might get. Zod does offer action but he doesn't offer anything new. He's just another kryptonian which I find dull and uninspired for a new film. Even as a Superman fan I want to see something new.
		
		
	 
The Superman that the GA has been mainly exposed to has been the Golden Age version, where Superman is presented as the 'Real Persona', not Clark Kent.
Truth be told, in the manner that Superman was presented in the Donner and Singer's films, he's hardly someone who audiences can really relate too.
And plus; the main inciting incident that led to Clark becoming Superman in the films was because his father (who was dead by the way) told him that it was his destiny to be Earths' savior.
Did we see him making that choice for himself, let alone coming to that decision on his own? Did we really see why he felt compelled to step out of the darkness and exposed himself to the world as Superman when he could have very well chose to stay in the shadows and just save people whenever he could quietly?
The only thing that we got was basically Clark going into the FOS not knowing what his purpose was in life, to just come out of it after 12 years as Superman after having one talk with his father.
I want to see something different from the Donner films. I want to see the journey of how the man of steel became Earth's greatest Hero, and I'm sure I'm not alone in this desire.
And from a story standpoint, since I'm a screenwriter myself, it makes more sense to introduce a villain like Zod imho given this stage in Superman's life. If he's just become Superman and had to learn on how to control his powers on his own, then he would definitely find it difficult to fight someone who's as strong as him. Given that Clark has probably never encountered anyone as strong as him before Zod, who is likely a trained fighter, Zod would probably end up owning him at times in the fight before Superman comeback with a victory, and that's more of a inspired fight for me than him fighting off several robots, etc.