Watership Down

So, I recently reread one of my all-time favorite books.  It's called Watership Down.  It has incredible world-building, endearing characters, vivid description, and a gripping storyline filled with foreshadowing and subtle clues.  Unfortunately, I can't seem to get anyone else to read it so we can geek out about it together.  Why, you may ask?
Because it's about rabbits.
Yeah, it may sound a little weird, but the author, Richard Adams, really makes it work out well.  And no, it doesn't make you decide to go vegan or anything.  It's not that kind of book.  It very much emphasizes the natural processes of the world while also exploring real emotions.  The characters are incredibly believable, but still very animal in their thinking.  It's a fascinating read, but no one will read it.
Why does the world have something against books about animals?  If these were human characters, this novel would be on the AP reading list.  Instead, we're stuck reading things like The Crucible.  Can someone explain this logic to me?

Fare thee well, friend!
Mira