When something like “Thor” comes to town, there is really no refuge to be found in drink, death or subtitles. … Mr. Branagh has not failed to make an interesting, lively, emotionally satisfying superhero movie, because there is no evidence that he (or the gaggle of credited screenwriters, or Paramount, the sponsoring studio) ever intended to make any such thing. On the contrary, the absolute and unbroken mediocrity of “Thor” is evidence of its success. This movie is not distinctively bad, it is axiomatically bad. And that is depressing. A howling turkey is at least something to laugh at, and maybe even something to see. But “Thor” is an example of the programmed triumph of commercial calculation over imagination.