It was just various scripts and schedules colliding until they could crank a movie out. The thing is, it's highly doubtful that Matthew Vaughn's Magneto movie would have been much better, even though they were the best parts of this film. That was down to Michael Fassbender's excellent face, and certainly not the script/directing/staging/anything else at all. Take the pre-credits Magneto sequence - kind of okay conceptually, but in execution hilaribble.