What are the strengths and weaknesses of this story?

I think the strengths come from its many allusions and symbolism. The title of the story also contains some preliminary information. The 137th psalm of the Bible is in the basis. The psalm appeared when the Jews were ruled by Babylon. According to Bible negative consequences are caused by the sins. Obviously, the loss of the land of the people chosen by God had some reasons. But the Jews didn’t leave their land for foes, they accepted their destiny but they fought for their possession. This idea is developed through the story as people made some mistakes (either conceptual or material) and now must live away. Through the silent obedience of Marvin we conclude about the acceptance of fate. Surely such idea doesn’t call us to be fully indifferent; it indicates the importance of our actions, understanding, and public awareness.