I suppose if the magic were used as allegory, or even as satire, I could see the subject matter being in the hands of someone conservative. I am just bothered by her depiction of all non-magical people as clueless sourpusses.
I know, the book is supposed to be fun. And granted, there are evil magicians, like You-Know-Who, and the existence of the “Dark Arts.” But in general I was bothered by what the alternative universe of Hogwarts represented: Diversity U, with Dumbledore as president.
I don’t think she was too hard on non-magical folk. If you’ll recall her descriptions of the clothing fashions and mistakes of the magical folk you’ll see she was making fun of them too.
Part of the problem is that aside from the Dursleys, very few muggles got described. In the last book, they were being punished severely, and the narrative seemed to be sympathetic to their plight.
But clearly, it is a story about magic, as is Niven’s. For those who cannot perform magic, it is as if they were handicapped in some way. In fact, the whole point of the conflict erupting in the final book was over the treatment to be accorded to the non-magical.
Why would Rowling be harsh toward non-magical folk? She KNOWS she is among us.
She did accomplish making learning magic seem to be as much drudgery as learning algebra...