I think the initial flaw in your logic is comparing Superman to X-men. Superman should be putting up Spider-Man numbers, not X-Men numbers.
The initial flaw in HIS logic...what about yours?
Your assuming a huge correlation between Spider-Man and Superman simply because what...they are the most well-known Marvel/DC icons? Um...how did you come to that conclusion?
There is no relevance or basis whatsoever for a belief that Superman should produce Spider-Man level numbers. None. What. So. Ever.
Point me to where it says that beyond your subjective opinion?
Spider-Man has a unique set of variables and standards that made it the hit that it was...not to say that Superman Returns bombed at the box office. Its universally accepted by almost anyone with a brain that WB had unrealistic expectations since Superman pulled more money that Batman Begins, which is considered a success.
Are you the lone one who is going to stick to the outdated belief that somehow this movie tanked?
And I think Maze brought up a terrific point by asking if Superman comics over the past ten years have done as well as Spider-Man comics?
If the answer is yes, then you're right.
If the answer is no, then you're "logic" has several flaws.
If the answer is "I don't know," then your logic is based on unfounded reasoning.
So, please explain this to us.