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.
I was about to say, unless the book is one where it displays that the person has a vastly opposing political, ideological, or other views that I deem personally important I wouldn’t judge them for any book they enjoy. Even if I don’t personally like a book, that doesn’t mean I think I’ll be incompatible with someone who does. That way of thinking is so snobby, and that kind of snobbery is what would make me swipe left.