But thing is: "Iron Man" was a big hit too (second biggest hit of 2008 after TDK I think) and it was pretty much exactly the right mix of comedy and drama that you'd want in a Superman movie.
The other big hits of the year included Indiana Jones, Hancock and Kung Fu Panda. Not every one of those movies was that good but they all adopted tones that, to varying degrees, were more in line with a character like Superman, Shazam, or even Wonder Woman and Green Lantern.
So obviously not all superhero movies have to be as grim and gritty as TDK to be successful. Unfortunately, if WM is a huge hit, as noted above, this will cement their thinking that they do.
