The more interesting question is: what do we do with the art of people who were revealed to be terrible? I first saw people wrestle with this idea for Michael Jackson and recently it has been a big issue related to Kanye West.
It's an interesting conundrum isn't it?
H.P. Lovecraft is a case in point - Lovecraftian horror is a special sort of literary genius, in my opinion, and massively influential on other writers to this day (I'm a big fan of The Laundry Files, for instance, which draw on it). But it's clear that he was massively racist, and significantly more so than just "well those were the times". Some people (some people here in this thread) say that we should "separate the art from the artist", but there's quite a bit of veiled and not-so-veiled racism in the art as well. Not to forget the misogyny.
So we decide to disavow him? No Cthulu for anyone! Well, that doesn't seem like a good option either. There's no easy, feel-good answer here other than to understand that flawed people sometimes create great art, to understand we don't have to (probably shouldn't) make idols of artists, and to be nuanced in our appreciation of their output.
In this vein I did enjoy reading "Lovecraft Country" a while ago, which both explored the horror of racism and embraced mythos-style themes.
Scott Adams gave us Dilbert. In the 90s I found it amazing. By the 00s I'd stopped paying attention, and then he started saying some somewhat less wonderful things which, if you squint, you could see foreshadowed in how uncharitable he was to people in his earlier writings. Another imperfect human, who gave us some good fun and insight, and in the end didn't live up to everyone's expectations. We shouldn't gloss over it, but perhaps we shouldn't pile those expectations on them anyway.
I had a decent lunch at Stacy's that time though...