We once read a book called “Feed” in high school - a ham fisted anti-capitalist book. Wherein citizens are 100% connected to an internet like service that only exists to sell them products. 90% of the class couldnt get it. Even when the teacher sat down and explained the entire plot of the book they still couldnt wrap their head around it.
From personal experience it’s because ppl didn’t read the book and are thinking about stuff closer to home. I would be lucky to have skimmed the sparknotes for most books in hs. It’s embarrassing to not know and get told off by teachers for it so it’s easier to just repeat some words and then “hmm, oh ok” when they explain it. Papers idk, maybe it’s just too depressing and pointless to fail a third of the class.