In an ideal world, Batman would be nowhere near this movie, but Warner Bros. know how well anything featuring him sells, so essentially shoehorned the Caped Crusader into a story where he's a passive spectator for the most part.
Batman takes front and center on the film's box art and posters in order to lure the casuals in, and he basically ends up being an audience surrogate, allowing other characters to explain things to him without it seeming too obvious that they're basically talking to the viewer.
Ultimately most of the action is of the supernatural variety, so Bats isn't much of a fixture and often just stands around watching, and things get even more egregiously pandering when you factor in cameos from the like of Superman, Green Lantern and Wonder Woman.
They've got no business being in the movie, and all it says is that Warner had no confidence in releasing the film on its own, which is a damn shame.
Stay at home dad who spends as much time teaching his kids the merits of Martin Scorsese as possible (against the missus' wishes).
General video game, TV and film nut. Occasional sports fan. Full time loon.