There is PLENTY wrong with TOBT. Plenty. So much so that there are many fandom ppl who don’t consider it canon.
I’ve seen attitudes about this book change over time. In ‘94, when that book was 2 yrs old, I remember ppl telling me they felt the series had ended with QOTD, bc TOBT was written off as simply being “the body-swap episode” (many films and TV series have tried their hand at that concept, and it’s usually a wacky ride). When Memnoch the Devil came out in ‘95, ppl didn’t like that one either, too offensive for its ideas about religion, and/or too preposterous of a plot; TOBT + MTD seemed to confirm that VC had jumped the shark, and a lot of ppl decided that the series ended at QOTD.
TOBT has wackiness in it, I mean, the difficulty of peeing (with a dick) is described in such vivid detail, there’s just too much comedy in it for me to discard it all outright.
(Oh! And perfect cinnamon roll Mojo the doge is in this book <3)
(Trying not to spoil it too much here but it’s pretty obvious what happens, but POSSIBLE SPOILERS AHEAD)
If TOBT was really just “the body-swap episode,” it could be written off as “wacky,” we could talk about the silliness of the details of the body swap, all that. We could even talk about how frustrating it was that Lestat went into a deal with a self-proclaimed THIEF and assumed that this dude would, you know, HONOR THE TERMS OF THEIR DEAL to the letter, but such were the poor state of the trust issues of our lovable but hamburger-brained moron de Lioncourt at that point in canon. He was also extra vulnerable to being taken advantage of bc he was feeling unworthy of life at all and pulled an Icarus ;A;

^So this was the cover for the edition that I read, it’s the first edition that was published. And the cover actually is relevant to this story, bc the statue you see here getting enveloped in a gray mist (it was a dull silver in real life) is The Rape of the Sabine Women by Giambologna in Loggia dei Lanzi. I’m not going to go into a deep comparison of this to TOBT, essays can be and probably have been written on it.
I think a lot of those ppl in 1994 who wrote TOBT off as “wacky” had not actually read it bc this book takes the body horror to a place that most body-swap episodes/films wouldn’t dare to go. There are major consent issues, sexual and otherwise. There’s rape. I think AR was exploring sin and consent, she unflinchingly went there. Some ppl in the fandom refuse to accept it as canon bc they did read it and are repulsed by how far it went with these explorations.
Personally, I always advocate reading the book, and stopping if you need to, or engaging with it however works best for you. I think there are good things in that book and I think Lestat changes through the course of the story. Improvement is not always an easy trajectory. Just like in real life,
improving oneself can be a struggle, and there are often setbacks, sometimes devastating. One could say he ends up worse than he begins this story, one could say he ends up better than he begins. Just because you read/write problematic things, does not mean you condone them.
Oprah walked out of a screening of IWTV when it was first in theatres. [X] Tom Cruise told her afterwards that he wasn’t surprised. “The movie is not for everyone.” Similarly with fiction. This book is not for everyone.

[^X The pic I chose of the statue is not from the same angle as the pic used on the cover, but you get the idea.]