Scott explores the paradox that while it's unfair to judge people/movements by their worst moments rather than accomplishments (like psychology or effective altruism), we all naturally do this anyway (like with Anthony Weiner), and he has no solution to this dilemma.
Longer summary
Scott uses the Scottish joke about MacGregor the bridge-builder (who is only remembered for one shameful act, not his accomplishments) to explore a paradox in how we judge people, fields, and movements. He argues this dynamic unfairly affects psychology (remembered for replication failures, not discoveries), effective altruism (remembered for buying a castle, not saving lives), and victims of cancel culture (remembered for one mistake, not years of good work). However, Scott admits he does the same thing himself - he can only think of Anthony Weiner in terms of his scandals, not his Congressional career, and can't stop himself from mentally categorizing people by their worst Twitter comments. He concludes by acknowledging this as a thorny problem with no good solution.
Shorter summary