Having taken the Hero's Journey class last year, the discussion of Billy Pilgrim's traits and value as a hero or protagonist was interesting to me. Although our curriculum has included a number of characters who deviate significantly from typical heroic classifications, I feel that Billy is especially unusual. He is not a dark, deep, brooding antihero, nor is he a morally-motivated hero of myth. In the vast majority of the scenes we see Billy in, he is devoid of passion and emotion entirely and takes complacency to an extreme; Billy is more willing to understand events as simply happening to him or the work of destiny as opposed to believing in his own capabilities. This perspective is of course only made more bleak by his curse of being "unstuck" in time, and although the exact details of what Billy could conceivably change are not explicated, it is apparent that he has no interest in interacting or altering the world around him in his past.
While this may make Billy Pilgrim unappealing or not relatable, I think Vonnegut does very well to create such a passive, defeated character as the protagonist for his anti-war novel. Aside from a pretty in-depth look at the effects of post-traumatic stress disorder, Vonnegut provides an image of the profound hopelessness and desensitization that results from war. The clearest indicator of this is Billy Pilgrim's repetition of the phrase "so it goes" whenever death occurs in the novel, perhaps also in an attempt to elicit a reaction from the reader. This acceptance is just one example of how simple Billy appears from an external perspective, and he was likely written to be of mediocre intelligence. Yet, are not the majority of people in the world average? I think in Vonnegut's anti-war efforts he is trying to make a point about how ridiculous it seems to soldiers in the thick of battle to fit killing and war into metanarratives. We've said that Billy's "so it goes" phrase devalues loss of human life, but perhaps trying to rationalize the deaths of so many is just as problematic.