Five communities actively disparage the benefits of expertise. This chapter explains why their criticisms are misguided. Experimental psychologists have shown that linear models can outperform experts, but the factors driving these models are drawn from experts’ judgments. The Heuristics and Biases community asserts that experts are prone to flawed reasoning, but ignores the ways that heuristics let us handle complexity and ambiguity. The evidence-based performance community wants practitioners to rely on best practices identified through carefully designed research, but ignores the cognitive challenges of handling incidents that involve multiple interactions and demand adaptation. Computer scientists have shown that artificial intelligence can outperform experts in games such as chess and Go—fixed tasks with little ambiguity. Some sociologists argue that expertise is just a social attribution, an ideological position that minimizes the contributions of individual experts. Studying these criticisms can help us discover better methods for supporting experts and fostering expertise.