Literature is often polarizing. You see many literary novels that get a U-shaped rating distribution, with most readers either loving or hating a book. I think the best explanation for this is the distinction between plot-oriented and character-oriented readers/writers. Plot-oriented readers want a logical development of events and will tolerate shallow and interchangeable characters (as in most hard sci-fi). Character-oriented readers want development of personalities and relationships, and have less demand for structure (as in much fantasy). Perhaps the controversy over The Rings of Power is an example of this.