There are a lot of great reasons to separate the work from the maker of the work. For one thing a writer's subconscious might help them write wisdom their conscious mind is having trouble grasping. Another reason is that art, even great art can be created by horrible, horrible people. Bill Cosby, Michael Jackson, Isaak Asimov, and a lot of others have given us insight and joy, while being less than they should have been or even monsters.
If you want to avoid their making a profit or their estate making a profit, then fine. This may be a good thing. But throwing out Harry Potter with an author who has internal demons, doesn't really help the world.
Niven was a joy, but he always felt a bit on the conservative side. Qanon has shown us how easily twisted the conservative mindset can be. To quote John Greenleaf Whittier, from his poem Icabod, "The tempter has a snare for all, and pitying tears not scorn and wrath befit his fall." https://www.poetryfoundation.org/poems/45486/ichabod By the way, Ichabod was written by an abolitionist in response to Daniel Webster, a hero of the abolition movement, voting for the Fugitive Slave Bill. https://owlcation.com/humanities/Ichabod-A-poem-on-the-Fugitive-Slave-Bill
Great men with great works have often had issues within those works. Mark Twain's Huckleberry Finn has suffered at times because it was sensitive to racial issues and at other times because it was not sensitive enough.
So while I still love the book, "Protector." I cringe at what foolishness Niven has fallen too. Especially on the issue stated. Truth is, that human health and failings in health care effect us all. If we think letting one person among us go without medical care and train them to fear it, we weaken us all. The anti-VAX people make us all less healthy. A person with a communicable disease that is avoiding or being denied care because of fear, oppression, poverty or politics, makes us all more likely to get sick. Niven is so insanely wrong. But then his ideas on Nuclear Safety have always been cray cray and without compassion.