This seems to be extremely common among artists and musicians, which I suspect is because their livelihood is tremendously dependent on reputation as it is hard

This seems to be extremely common among artists and musicians, which I suspect is because their livelihood is tremendously dependent on reputation as it is hard to objectively judge their work. They have very high standards to meet and very little room for error, hence the tendency for extreme perfectionism, even to the point of destructive behavior. Johannes Brahms, who spent more than 20 years composing his first symphony, did not want to be judged on the basis of any of his unfinished works or personal letters, so before he died he dumped them all into the river. Jean Sibelius burned the manuscripts of almost everything he attempted in the decades after his final published work. Camille Saint-Saëns suppressed his now-famous Carnival of the Animals because he thought it was too immature for someone of his stature and that people would stop taking him seriously. I think the effects of impostor syndrome become greatly magnified when one has a reputation to protect, especially if it's one that would persist after death. But I think most of us can find some comfort in the words of Sibelius: "Pay no attention to what critics say. No statue has ever been put up to a critic."