very serious books

Several children's literature listservs have been discussing the dearth of children's books with non-white characters, written by people who aren't white, that are faithful to that culture. And I'm sympathetic to that - I quite see why you'd want the illustrator to be familiar with, say, Hmong culture before illustrating a book about a Hmong child. And I'd like to see more good books featuring a variety of main characters who aren't the cis-gendered, Caucasian, heteronormative, able-bodied characters we've all seen so often. Of course I would.
But I would also like to see more diverse books that are fun to read and well-written. More Absolutely True Diary..., fewer - well, I won't call out any book in particular, but I will say that one of the contributors to this discussion has written a book that is undeniably praiseworthy for featuring a slice of non-Caucasian life, but it's also too lengthy for the target audience, and it's dull. It seems like an elephant in the room: one can quote statistics about how many books are written by, say, Asian authors about Asian characters (=not enough), but then one should also subtract the ones which, candidly, won't be read with enthusiasm by most people.