Watchmen the comic book was a dissection of other comic books at that time. It was in many ways the grandfather of the modern, serious and dark comic book.
The film tried to do the same with comic book movies, although Nolan had already done two serious films without the satirical elements. Everything was exaggerated, ridiculous suits, campy action, out of place pop music. This was all intentional. Snyder has mentioned this in interviews, but I don't think it came across well enough in the actual film. There's a fine line to walk on with material such as this, and Watchmen didn't always nail it.
I can't figure out if the film was a few years too late, or a few years too early.