Zack Snyder is misunderstood.

Reviews for his new movie, “Batman v Superman: Dawn of Justice,” have been mostly unkind, with several singling out the film’s bleak tone. “Blunt, humorless, and baffling, it collides the brutish directorial stamp of its director … with the most shameless instincts of our latter-day superhero franchise bubble,” Jonathan L. Fischer wrote for Slate.

But...