Given how Eddie's setting in Fresno is constructed, the navy is a desirable alternative. Anything would be better than what Eddie experiences in Fresno. Yet, in seeing drawbacks to the navy, one would have to point to how Eddie "flees" to the navy. There is little to indicate that Eddie is actively choosing his path. He turns to the navy because of no other options. The fact that the van which takes him to the naval base breaks down and Eddie is in the middle of the desert is symbolic of his own condition of emptiness. Eddie looks at the vast desert and realizes that this is his life. Eddie has not actively chosen the navy, which can be a drawback because of his lack of agency.
Another potential drawback in joining in the navy is that Eddie still lacks the capacity to address life in Fresno. While the ending might point to some type of resolve reached in terms of his life in Fresno, there is little psychological evidence to suggest that Eddie is truly equipped to challenge the demands of Fresno life. Once his tour of duty ends in the navy, the reader is not entirely convinced that Eddie could come back to Fresno and live his life as an active individual. Fresno still challenges Eddie so much. There is little to indicate he is ready to handle all that such arduous elements present. While there might be a chance in Eddie as a result of the navy, one is left to wonder how Eddie will fare when he returns back to Fresno and the people in it who seek to travel off of the straight and narrow.
In this regard, Eddie's move into the navy can be seen as possessing drawbacks. Eddie has not chosen the navy as a deliberate choice that reflects his own activity. Rather, Eddie has taken sanctuary in it. While this might be a skeptical view, it is reflective of a world that has caused him much in way of challenge and suffering.