Take a look at the title of this difficult story: We Were the Mulvaneys. The implication is that the trauma and tragedy of Marianne's attack drove the family apart. By saying, we were the Mulvaneys, Joyce Carol Oates is suggesting that they are not a family anymore. In that way, the novel seems to be both about Marianne, and also her father. The novel explores the ways violence disturbs a community, showing that rape and other kinds of violence against women are communal issues.
The question on the table is why should Marianne's father be able to play the victim? For instance, he rejects his daughter out of his own frustration and confusion (not to mention the trauma of finding out one of his business colleagues raised the kind of son who would rape an innocent child). Apparently, the attack was so disturbing in nature that just knowing about it drives the father crazy. When his alcoholism and dysfunction drive the family apart, the question is whether he has done Marianne justice, but the novelist is compelling. Any parent could explain why the father is affected so deeply.
However, his failure is still to be regarded as a failure. By failing to allow his own daughter to grieve in her own way, he betrays her. She needs a stable support system, but instead he makes her into a loner and a vagrant. She has to deal with the trauma alone.
This loneliness might not be the father's fault entirely, though. The most charitable interpretation of this novel would be that Marianne's loneliness is the consequence of her rape—not something to be blamed on the father. The father's hope is removed from him by the traumatic event, so instead of "blaming the victim," the reader should consider that perhaps the true effects of violence against women are communal. The father's mental instability represents the drastic nature of the event.
