Tell that to the comic.

Comic books and movies are two VERY different forms of medium. Just because something works on a comic page, doesn't mean it will translate to the big screen. Comics provide immense creative freedom for its writers: they can fit dozens of lines of dialogue and convey multiple character actions in a single page, in a comic book of 50 pages, in a series of 12 issues. See the problem here? A comic book story is usually divided into multiple issues so that writers can illustrate the story effectively, whereas a movie has to tell a story within a 2 hour time frame or else audiences will simply get bored/tired, and two hours isn't anywhere near enough time for all of Marvel's characters to be given enough screen-time, dialogue or significant impact on the story without being shoe-horned into the narrative for fan-service. Don't get me wrong, I'd LOVE to see Spider-Man standing next to the likes of Hulk and Wolverine, but I care about the quality of a movie first, and seeing as the current companies that own the rights to characters know they're sitting on a gold-mine because of the characters' appeal - it currently just isn't a possibility.