I've refrained from discussing the Roman Polanski thing until now, but Jim Lindgren's quote of George Orwell at the Volokh Conspiracy expresses what I think so directly that I'll quote it here. As Lindgren says, "good artists are not necessarily good people and bad people are not necessarily bad artists." Dali was Orwell's subject.
What Dali has done and what he has imagined is debatable, but in his outlook, his character, the bedrock decency of a human being does not exist. He is as anti-social as a flea. Clearly, such people are undesirable, and a society in which they can flourish has something wrong with it. . . .
[. . .]
The artist is to be exempt from the moral laws that are binding on ordinary people. Just pronounce the magic word “Art,” and everything is O.K.: kicking little girls in the head is O.K. . . . It is also O.K. that Dali should batten on France for years and then scuttle off like rat as soon as France is in danger. So long as you can paint well enough to pass the test, all shall be forgiven you.
One can see how false this is if one extends it to cover ordinary crime. In an age like our own, when the artist is an altogether exceptional person, he must be allowed a certain amount of irresponsibility, just as a pregnant woman is. Still, no one would say that a pregnant woman should be allowed to commit murder, nor would anyone make such a claim for the artist, however gifted. If Shakespeare returned to the earth to-morrow, and if it were found that his favourite recreation was raping little girls in railway carriages, we should not tell him to go ahead with it on the ground that he might write another King Lear.