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.
Ender’s Game weirded me out with the naked kids floating around a space station that’s theoretically a military training facility. Or Ender beating a kid to death in a fistfight when they’re what, seven? Like the preteen gang bang in IT: What narrative purpose does it serve?! Other than weirding out the reader and making them uncomfortable I’m not sure what it could be.