If you're a writer, a musician, an actor, a director, a poet; if you are good at intelligence and espionage, a great librarian, a doctor, a researcher in science, or even a good cook and you're a racist or sexist the typical response is to say, "Evil! Evil! Not only is he fired and his memory disgraced, but we must now revoke any honor, remove any plaque or statue, deny any advancement, extirpate his presence in music or art or film or the culinary arts, and let his name be unmentioned forever." It's to the point that some want to see their families destroyed and suffer, for the person involved to be fired from work and unemployed.
I think that's foolishness writ immense, but that's the way it's done these days. I think you're right. If what was done is worth being read or heard or seen or learned, then what was done is worth being read or heard or seen or learned even if we find out that the person behind it violates our morality. Pasternak wasn't a Communist, but wrote good Russian lit under the Communist regime; banning his works was an act of the inquisition and protecting the flock from seeing a evil man as a role model, which is the act of oppressors wanting to control and manipulate, not of those given to freedom and self-determination. Of course, in the USSR since the government provided all jobs and housing, the call for firing the person for political unreliability automatically meant he was a "parasite"--it was in the USSR that being unemployed was actually a prosecutable crime--which could lead to state-required homelessness.
"This man did X, Y, and Z, all good, and we have his statue for this reason. But he did something now considered bad, so we must pull down his statue and chisel his name from off the stelae that recount that portion of our history." It's like the Egyptian god-kings' response to Akhentaten's apostasy.
Or like fundies' response when they learn that some novelist was gay. The moral taint is assumed to spread thoughout everything the person did, and assumed to continue to spread by contact with the work.