Why do the words none of this is anyone’s fault make Ishmael angry

Once he recovers from his undirected rage, Beah concludes that if Gasemu had not delayed them, he would have seen his family. He attacks Gasemu, eventually striking him with a pestle. The other boys hold Beah back again; Beah’s anger infects them and they turn on one another, some blaming Gasemu for their not rejoining their parents, while others defend Gasemu as innocent of any intentional harm. Gasemu intervenes to stop the fighting, insisting that “None of this is anyone’s fault.” The fact that none of the children, and most of the population, is responsible for the war is a motif throughout the book. Beah and the other children are frustrated by the hell they are in and the people responsible do know or care about what these people are put through.