I think you're conflating people being defensive when someone rudely comments on a video or content to tell CoHo fans that she's terrible (and therefore the fans are terrible) with an actual lack of literary criticism and discussion. People read for a variety of reasons and some don't want to break down the structure of a book or talk about the writing outside of their subjective enjoyment.

If you're looking to try to break down the structure of a book you dislike to understand why you may not like it, I'd suggest studying writing to be able to recognize those things and be able to discuss them with more confidence. You can also seek out content that better fits what you'd like to see in book reviews and book discussions, which may help you grow that way as well.