I'm not a big fan of non-SF novels after the mid 20th century, so I can't comment on any of these specifics, but some artists being awful in their personal lives has a long record in history.

Richard Wagner - the guy who created Der Ring des Nibelungen - was a vicious anti-Semite (although this was pretty standard in 19th-century Germany), brutal to his wife and children, and had numerous affairs.

Roman Polanski is a similarly awful person who's triggered some of these same debates about his works. Whoopi Goldberg's comments dismissing his sexual assaults against young girls as "not `rape-rape`" is an example of people defending him. Some even argue that he's a "political refugee" for escaping justice by fleeing to Europe, and should be pardoned as a sort of award for his artistic genius.

Woody Allen. 'Nuff said...

And yes, Allen and Polanski's art and their artistic reputations will likely endure long after they and their victims are dust, with their personal awfulness being a historical footnote, as it has with Wagner et al...