Here's why people think Zod is repetitive.
When SR came out, and a lot of people hated it, they didn't take long to notice that the plot was very similar to Superman: The Movie. So some people joked, "Hey! I bet if they make a sequel, Singer will just copy Superman II, and Zod will be the villain!"
And that joke got repeated over and over. Until it wasn't a joke any more. People started to believe it, until it eventually became a fact, like it was confirmed that Singer was going to do it.
And then as time went on, simply mentioning Zod got cries of anguish, people asking for something 'new', almost as if a sequel to SR had in fact been released starring Zod. And in their minds, it sort of had.
The Superman boards are a strange place.