I find it hard to appreciate art that revels in torture, graphic violence and emotional abuse as an end unto itself.
If you want an example of science fiction as high art, personally I would suggest Vernor Vinge (specifically A Fire Upon the Deep and A Deepness in the Sky) and Ursula Le Guin.
I wouldn't agree that BOTNS "revels" in violence or torture at all. I personally wouldn't enjoy a book that revels in torture or violence, but I've read the BOTNS series many times (5 or 6). Sevarian clearly doesn't enjoy his path nor does he "revel" in it and if anything he generally tries to avoid violence. Gene Wolfe as a man clearly doesn't focus on violence and certainly doesn't celebrate it, it's just a small but real part of the world both in reality and BOTNS, and I think it's an important thing we have to explore in art, which is the violence of man to man, why it exists, why we do these things.
I can see how you get there, but strongly disagree with that assessment of BotNS.
It’s far from an endorsement of torture and abuse. Master Gurloes is a deeply broken man. Severian’s childhood trauma colors the entire story, especially his relationships with women. Part of Severian’s maturation throughout the books is his slow abandonment of his life and identity as a torturer.
To get anything out of BotNS you need to separate yourself from Severian’s point of view, and Wolfe makes this deliberately difficult. There’s what Severian believes, there’s what he wants us to believe, and there’s what “really” happened. Between those three poles there’s usually a lot of empty space.
Even if Severian has become a better man by the end of the BotNS, in the coda to the sequence The Urth of the New Sun he is still keen on bedding the women he comes across. From reviews and fora discussions, it is this constant interest of the male protagonist in casual sex that has turned off many female readers. Sure, the encounters are now consensual, but Severian remains a horndog, and it leads those readers to assume that Wolfe was indulging in puerile fantasies.
Compare the similar "eww" reaction to Larry Niven's The Ringworld Throne where the author kept describing the characters' casual sex with the locals of the places they passed through.
That’s a different claim than parent, but I see where you’re coming from.
I’d argue that Wolfe’s other work shows that even in Urth that aspect is more about Severian than Wolfe. Long Sun for one certainly takes a very different tone, but you could argue it’s the work of a more mature author.
BOTNS does not revel in graphic violence, in fact most of the violence in the story happens "off-screen" so to speak. It's also completely wrong to say that those themes are written as an end unto themselves, that reads to me like pretty much the exact opposite of the book. I'll presume you read it since you're offering such a strong critique, so I'd be curious to understand why you think this way.
If you want an example of science fiction as high art, personally I would suggest Vernor Vinge (specifically A Fire Upon the Deep and A Deepness in the Sky) and Ursula Le Guin.