I’ll go with the low-hanging fruit: Mein Kampf. I’ve read it, cover to cover. As a piece of propaganda, it’s good. As an example of good writing? Absolutely not (though I will admit I have only read it in translation). Oh, and the whole fascist, racist, and generally shitty worldview of the author that he infuses into the text. And the fact that the author is literally Hitler. You 5-star that book? You’re a Nazi. Period. And as a Jewish person, I don’t look too kindly on them.
Is nuance not a thing? Only good or bad, like or hate, 5 or 1. Nah.
Is nuance not a thing? Can I not rate a book that fulfillls its function perfectly as 5 even if it’s prose quality isn’t as good as a 20th century classic that fulfills its own function perfectly? Can I not rate 2 separate books a 5 out of 5 for completely different reasons?
You can do whatever you like. I don’t personally get it, but okay.
Youre the one who demanded nuance but refused to acknowledge there’s nuance to what criteria people use to give out (personal) book ratings.
Unless you create a standardized criteria it’s all just based on what the reader wanted and how well the author delivered on expectations