What a conundrum! To all the haters, while I understand your disappointment, it's really not that bad. It's just not the book it should, or could be. Instead of a fabulous tale of the Wicked Witch of the West, its a disjointed recounting of the life of an inexplicably green woman named Elphaba, involved in personal and political intrigue, roughly linked to the events and characters of another book.
If Maguire had decided that he was riffing off the Wizard of OZ, he should have delivered a story with the tone and characterisations of the original. If he wanted to deliver us a story about an imagined land with a complex political landscape raising challenging moral questions, he should have invented his own world and characters - and could still have paid homage to the original. But instead we have a muddle.
The book starts well, we think its actually about the life of the WWW, we're going to have some questions answered. But just as things become interesting it skips over an immense and critical part of her life, suddenly she's in university. It seems that Maguire has become impatient to get on with the POINT of the story, which isn't Elphaba at all, its the Wizard and the political machinations in OZ. While Elphaba is in the Emerald City, her point of view bears some usefulness to the story, her friends and her school have a role, it's still - sort of - working.
But with each chronological jump, Elphaba is further away from the crux of the action. We don't have eyes on the Emerald City anymore and we're not really seeing her develop 'evilness' - in fact she's one of the few moral characters, nor do we see Glinda, or much of her sister, or the 'city' characters. The political issues are presented without depth or discussion, although they are becoming the main driving force for her beliefs and actions. For Elphaba it seems to be all about Animal rights but surely there is more to it than that? But when her sister secedes Munchkinland, Elphaba refuses to involve herself (although in her sister we have a nice portrait of a charismatic fundamentalist leader). In these many pages in the second half of the book, the story is flat. It's hard to know where we're going with all this and difficult to maintain enthusiasm for series of events that don't develop Elphaba's story.
For a story allegedly about the Life of the WWW, Maguire doesn't want to explain much; why Elphaba is green, why she is hurt by water, why her sister has no arms, how she ended up at the Maunts, how giving birth seemed to escape her attention, who the hell is Yackle and much more. Not even why such a passionate Animal righter would sew wings onto monkeys! There are clues, but not any that are really satisfying and unfortunately these are the very questions we the reader want answered.
To be fair, he does a decent job of bringing the conclusion of the story into line with the Wizard of Oz, but do we reach this conclusion having enjoyed a rollicking tale of the Life and Times of the Wicked Witch of the West? Not really. For all that its a decent read, just make sure you know what you're getting into.