I think his obsessive adherence to method acting is one of the main reasons he's a highly strung princess. He's convinced that he takes his work with deathly seriousness, the idea that anyone else might do less than that drives him wild. He's also been in the business for a helluva long time and actors who've been child stars often aren't the best adjusted peeps out there.
The funniest thing about Bale out is that it took place on the set of a McG directed movie. It's bonkers to get uptight when the film is so shite anyway. imho