Banning books is generally upsetting but banning Steinbeck’s masterpiece is insane. If I put my brain in neutral and think about through a scope of ignorance I can surmise a few points. There are racial slurs in it, especially against Crooks the Negro ranch hand. There is some mildly offensive language, although it is rather tame compared to today's standards. The whole euthanasia scene at the end of the book would have ruffled some feathers. Ending someone's life (euthanasia) is general taboo that got Steinbeck's novella banned. In the end, it is sad that this novella had limited access in any sense. Of Mice and Men is truly a great piece of fiction.