To my mind, the Harry Potter books began with two huge missteps. First, the game of Quidditch, whose scoring makes no sense except as a vehicle for You Know Who to be the hero of every single match. Second, the Dursleys, who are presented as villains, whose cartoonish abuse of Harry also makes no sense from the point of view either of plot or character. Both have obvious story goals: they accentuate Harry’s journey from Privet Lane, where he’s the most abject of victims, to Hogwarts, where he’s a beloved hero. But they’re both overdone in ways that can’t be walked back as Harry grows up and the later books become more serious in tone.
One the (idiot) rules of Quidditch are stated, that’s it. Rowling has lost the opportunity to make it a game anyone other than the Seeker would bother playing. And once she’s established that the Dursleys treat Harry in a way that would cause the British version of CPS to remove him from their home and file criminal charges immediately, she can’t make the portrayal any more sensible. Contrast this with the progression of our understanding of Harry’s ability to understand snake-talk. Ar first, it just seems like another one of his magical talents Later, when it’s used against him by a faction that’s suspicious of him, we learn that it’s a power associated with dark wizards. Still later, we find out that it comes from a bit of Voldemort he absorbed when Voldy wasn’t able to kill him, and that that makes Harry a horcrux who has to die before Voldemort can be killed. Rowling cleverly left room to change and expand the meaning as we learn more about the characters and the story.
This is a damned shame, because Aunt Petunia’s attitude toward Harry (and magic in general) is complicated and something we learn more about as the story goes on. As a child, she resented it, because it meant that Lily was special in a way that she wasn’t, and was a bit repulsed by it, because the only other wizard she know was the lower-class, unpleasant Snape. Add more resentment as her sister got a rich, handsome husband, and then horror, because it got Lily murdered. And then fear, as Harry came to live with her, and she knew that the danger he was in might threaten her family as well. A subtler presentation, where what seems to be simple abuse of Harry is really a combination of denial that he’s a wizard (which would keep both him and the Dursleys safe) with complete terror whenever he does anything out of the ordinary, would have been far more rewarding. Also, as things stand, it makes no sense that Dumbledore would allow Harry to grow up under those conditions. He’s got bitter experience with what young, powerful wizards become when raised in an atmosphere of isolation and abuse.
To look at this another way, there’s no need for Harry’s foster parents to have been villains at all. In many ways, Harry is King Arthur: hidden for his own safety, raised by foster parents, unaware of his true heritage, seeming to be far less than he really is until his true identity is magically revealed. Traditionally, Arthur was raised by his foster father Sir Ector and his foster brother Sir Kay. The legends don’t say a great deal about them, other than Kay being a bit of a braggart. In T. H. White’s The Once and Future King Arthur (nicknamed “The Wart”), as the younger son, is slated to become Kay’s squire, and since he worships his brother, he wants nothing more. When things change, it’s a bit of a wrench. Here is the scene after Arthur pulls the sword from the stone:
“Sir”, said Sir Ector, without looking up, although he was speaking to his own boy
“Please do not do this, father, ” said the Wart, kneeling down also. “Let me help you up. Sir Ector, because you are making me unhappy.”
“Nay, nay, my lord,” said Sir Ector, with some very feeble old tears. “I was never your father nor of your blood, but I wote well ye are of an higher blood than I wend ye were.”
“Plenty of people have told me you are not my father,” said the Wart, “but it does not matter a bit.”
“Sir,” said Sir Ector, “will you be my good and gracious lord when ye are King?”
“Don’t!” said the Wart.
“Sir,” said Sir Ector, “I will ask no more of you but that you will make my son, your foster-brother, Sir Kay, seneschal of all your lands?”
Kay was kneeling down too, and it was more than the Wart could bear.
“Oh, do stop,” he cried. “Of course he can be seneschal, if I have got to be this King, and oh father, don’t kneel down like that, because it breaks my heart. Please get up, Sir Ector, and don’t make everyhting so horrible. Oh, dear, oh, dear, I wish I had never seen that filthy sword at all.”
And the Wart also burst into tears.