With a short phrase, I can summarise the main problem Jim Adam saw with some of Rowling's books: plot over characters. Adam suggested that Rowling's meticulous plotting (which could possibly be some of the most intricate work seen since Shakespeare's day) was responsible for undermining her characters. He says it a lot better than I can, but I will just give a few examples that he raised:
(a). Harry is saved in the Chamber of Secrets by calling for help and receiving a hat, a phoenix, and a sword in return. The phoenix conveniently does 75% of the dirty work for Harry by destroying the basilisk's eyes. Then the phoenix also heals Harry when the basilisk bites him. This magnificent deus ex machina conveniently keeps our hero from getting into any serious trouble. The reader is terrified Harry is dying - and then: "Oh, wait, he isn't. Wonderful. A miracle healing." This is an example of great planning - Rowling mentions phoenix tears earlier in the book, as well as introducing Fawkes the phoenix. There is also some interaction with the Sorting Hat additionally. However, the result is that Harry - without having done any serious planning or magic (and only having brought Ron and an idiot professor for aid) - is saved by a Series of Fortunate Events. So Jim Adam says. I agree with him by about 60% in this case. The result? Harry has not hugely grown as a character. However, due credit must be given for his destroying the horcrux.
(b). Harry is saved from Voldemort by Dumbledore, at the end of book five. The headmaster conveniently shows up to send the Dark Lord packing. Dumbledore's great power and omniscience has already been established, so J. K. Rowling is well set up to use him as a saviour figure in the climax. The only trouble is, Harry fails to have a serious face off with the Dark Lord. Voldemort isn't scared of Harry, who (to quote the book) leaves his wand pointing "uselessly at the ground" when our snake-faced friend appears. Instead, Dumbledore looks huge while Harry looks small.
(c). After Dumbledore's death in book six, the Death Eaters who have infiltrated Hogwarts decide inexplicably to flee, even though the Order of the Phoenix haven't seriously harmed them yet and Harry is only shouting singularly useless incantations. Voldemort should have been part of this plan, so that he could show up and take over Hogwarts, killing Harry. It would have been an ideal time, since the only one he had feared was dead and there was a still way into Hogwarts. However, we have a Voldemort-less climax, so that - for the plot's sake - Harry can finish him off in book seven, instead getting creamed in book six. Hence, Voldemort looks a bit vacant in his book, in more ways than one.
(d). Harry's victory over Voldemort is largely because of the Deathly Hallows and because he knew one piece more of the plot than the Dark Lord did. How does Harry vanquish the most powerful dark wizard of his time? He figures out a few minutes before Voldemort does who the real owner of the Elder Wand is. Then Voldemort polishes himself off. Adam posits that Harry is able to rise from the dead partially because the Elder Wand couldn't completely kill him. In the end, Harry doesn't have to know any special magic or be ready to fight for his life. Instead, he just has to be aware that he disarmed Draco Malfoy earlier in the book. Clever plotting. Sadly, even after that wonderful moment where Harry actively decides to sacrifice himself, he still finishes the book still looking a bit like an innocuous school boy who had a jot of luck on his side. Was this Rowling's intent? I'm not sure. Adam talks at length about this in his book.
The added problem with this ending is that it seems to suggest that if we just have love, our enemies will fall eventually, even if we don't actively attack evil and destroy it. If we have love, our enemies will pop their clogs after a while, and we won't have to dirty our hands to show where our loyalties lie. Again, not sure if this was what Rowling intended. But unfortunately, I was left with something of this feeling. I certainly felt that the final victory was unrealistic.
All this has brought something to my attention. J. K. Rowling was a planner. She had everything planned out in her series. But is it really a good idea to have a detailed plot and to stick to it meticulously? A friend of mine recently said that her characters in her novels obey her perfectly. I seem to have trouble with mine. However, reading Jim Adam's book has alerted me that perhaps this isn't always a bad thing.
Perhaps the characters should be driving our plot - not us. Perhaps we should outline the villain's goals and the protagonist's goals and then just leave them to it.