Holly Black's "Tithe" is categorized as "Young Adult" fiction, but I don't intend to let that sway my judgment. I agree with John Green, who said that "Teen readers are not looking for characters they can identify with. They are looking for characters that they recognize are not bullshit!"
The main character is an outsider, a girl who works to provide her mom with money and food. When things go badly in the first chapter, they return to New Jersey and Kaye falls back in with her friends from six years prior. I found Kaye to be a very unlikeable character, and her former friends are barely two-dimensional. The relationship she has with rings false to me, and if Janet was once her best friend, that relationship is even worse. Is it because Kaye was that much of an outsider? The author never lets us know.
As Kaye was growing up, she had friends that were faeries. These three characters are also completely undeveloped, but then they are alien to our way of thinking. Other fae appear in the novel, and a few of them are less than completely wooden – but again, none are the least bit likeable.
A character who strives for likeable is Corny. He is the older brother of Janet, and is the vehicle (literally) through which much of the action happens. Other than that, he is underdeveloped, and when he does something outside of the norm later on, it really doesn't make sense. No explanation is given either; perhaps a later novel in this series revisits this character?
In my opinion, the characters and situations don't pass the bullshit test, and the writing is worse. Each chapter seems to be a scene, and there is little to connect the episodes together. In most cases the writing is inconsistent, the dialog is dull, and most of the book feels unpolished. On the positive side, some of the ideas are interesting and the descriptions of those are very colorful – one sees that these paragraphs were well loved by the author. Jarring the reader out of those are sentences like "she wanted to cling to the facade of humanity with both fists" which both confuse and annoy me. Literature this is not.
I couldn't find any details for why this is on a "banned book list", but I can guess. In the first few chapters there is an excess of hard alcohol (and these are teenagers?) along with quite a bit of swearing (yup, these are teenagers). Other possibilities are the occultism of the Faerie, or the potential Sadomasochism of one of the characters.
The book ends with our unlikeable character going through life altering events (unchanged) and ends with a romance novel kiss. I can't think of a book I was happier to see finish. Rebecca Stead points out that "kids grapple with big stuff" – in this disappointing book, that stuff goes mostly unremarked.