So should we get rid of most world mythology before or after we lock him up? Because incest abounds in a lot of it. Even Tolkien had an incestuous affair in the Children of Hurin.

If you read his depictions of incest as something that was meant to arouse the reader then you're the one with the problem, I'm afraid.

And no, interest in the books hasn't declined. The show was only ever entertainment but the books are, quite frankly, the most fascinating work of "fantasy" ever written. I say "fantasy" because what Martin has attempted is to drag the genre, kicking and screaming, back towards mythology - an allegorical tragedy.

Lastly, A Song of Ice and Fire, is the most feminist work of "fantasy" I've ever read. Martin is a noted feminist after all. Don't believe me? Then explain why the vast majority of commenters on the books, on both the forums and youtube are women; all of whom see it as a feminist text. Please, at least read this short essay, it will give you a brief insight into what Martin is trying to say:

https://plowmanskeep.wordpress.com/2019/09/02/the-great-goddess-in-asoiaf-part-i/

Unless of course your brand of feminism believes that even depicting sex in writing is fundamentally evil and abusive. Which might explain why so many women would rather put up with dealing with "trans" rather than come anywhere need the convent of anti-sex feminism.