Why do the poorer people tend to prefer grand narratives? Because the higher the uncertainty about the future, the more they need a sense of "meaning." When individuals find it difficult to change their fate through personal effort, they have a low sense of control and are more inclined to believe in macro forces. Real-world change is hard, but "believing in a grand explanation" costs very little and can provide: emotional comfort, self-rationalization (it's not that I am incapable), and a sense of direction (even if it's illusory). Additionally, lower-resource groups are more likely to encounter simplified, emotional, and macro-level information, making it easier for them to understand. Therefore, the less controllable reality is, the more people rely on grand narratives to find explanations, order, and hope.