I personally liked the book, flawed or not, and it was on the curriculum for a Year 11 English class I taught. Not only is it an interesting and fun read for most people, it's a good exercise for a reader to try to put themselves into an unusual mental space different from their own, and to try to relate. The book was on the Catholic school curriculum in order to promote understanding of one another and our differences in world view/modus operandi, both in general and specifically with groups of people with certain "labels" on them, and from my experience with students, it does exactly that: Promote a curiosity about difference instead of dismissal and judgement, and improve interpersonal interactions.
I also took the same novel into a low-achieving focus group (small group, more teacher attention, less pressure) Year 9 English class who had self-labelled as "English veggie class" and who had self-confidence and self-esteem issues that were intricately tied into their low achievement, so needed boosting up. I'd seen their suggested study novels and honestly, they were insulting for a bunch of 14-year-olds - primary level, socially much younger than their own age. So I floated with them the idea of giving them the same novel as my Year 11 ("normal") class was studying, and at first they were like, "Miss! We're the veggie class! It will be too difficult for us!"
I made them a deal. I'd bring in the book and we'd spend a lesson taking turns reading it. (When we read stuff out loud they had the deal that they could say "bing" if they wanted me to pronounce a word they didn't know, and that itself was super fun and always made people laugh.) At the end they'd get to vote as a class whether we were going to continue with it or not.
They totally loved it, and unanimously voted to continue with it. Reading it out, they were also like, "Miss! It says the f-word here! Do I say that? I mean, this is a Catholic school!" and we had a laugh about that and I talked to them about social realism in literature. But they were completely absorbed by the story, and it got them talking, in a good way, about disabilities and differences and how people are people and we can love and value those who socially tend to face a lot of rejection (and of course, this hit home for them, because of being in a low-achieving class and some people looking down on them for it). They actually got passionate about reading this book - and this is a class of people who struggled with reading and literacy - and improved in leaps and bounds with their reading, writing and oral communication as a result of studying that novel.
Afterwards, the students said, "It was so good to have an interesting book for a change! One that wasn't dumbed-down like we were Grade 1. Just because we don't read and write well compared to standard classes doesn't mean we're totally dumb and backwards in every way." And they felt so good about having done a senior-level book, and the fact that their class grade average had jumped one grade that term, with that project. Well, passion and interest and involvement always help us learn...