Well, how do you hold anyone accountable for behavior that is not strictly illegal, but is still not acceptable? By denying them the fruits of their bad behavior. Now, what with him being dead, and most of his works being public domain, we cannot deny him financial fruits. But what do dead people still have?
Herodotus writes of a meeting between Solon, the great lawmaker and statesman of Athens, and Croesus who was king of Lydia and fabulously wealthy. Croesus did his best to impress his guest by showing him all the opulence he enjoyed and regaling him with tales of all the territory he gained over the years but Solon was unimpressed. Angrily, Croesus asked if Solon had ever known a happier man in all his travels?
Solon: Tellus of Athens.
Croesus: How was he happier?
Solon: Tellus wasn't rich or poor, but he lived to see all his children give birth to their own and he died old and respected volunteering to fight for his country.
Solon is able to give other examples of common people he's met who were happier than Croesus which further infuriates the king.
Croesus: Am I so despised that you compare my happiness as less worthy than common men?
Solon: You are rich beyond measure, and I am sure at this moment no man may fulfill his every fantasy quite so well as you in the whole world. But I have seen men just as rich as you die more ignoble deaths than that the poorest of men.
You should count no man as happy until he dies.
Lovecraft's legacy, the legacy that he knew at least, was that of a near destitute, unsuccessful, largely unknown writer who died of cancer at a young age. His writing barely allowed him to eek out a living and he had no idea much more successful writers like Stephen King and Neil Gaiman would count Lovecraft as one of their influences. As far as Lovecraft was aware, his legacy was that of a failure.
So, making it so that whenever people hear "Lovecraft" among their first thoughts are, "oh, that racist shmuck who wrote horror," takes the good name.
Except I don't think it really does. So long as people play
Call of Cthulhu or are influenced by his writing, his legacy lives on. Maybe people recognize that he was a racist shmuck, but his legacy is largely intact.
Lovecraft Country takes his work, and turns it around and makes the targets of his racism into the protagonists. It makes people like Lovecraft himself into villains of the piece. Lovecraftian themes used in ways Lovecraft himself would not agree with, and indeed to counter his own ideas. It helps to have better written prose than Lovecraft, which admittedly isn't that hard. These things rob him of the propagation of the problem into the future.
It doesn't rob Lovecraft of anything. He's dead. And I wonder how many people read/watched
Lovecraft Country and went over and started reading Lovecraft?
Lovecraft Country elevates Lovecraft in many ways. Despite knowing about his racism, the main character still enjoys reading his work. It's kind of like how even anti-war movies seem to glorify war.