Wizard waves a rainbow flag
Renewed calls for ban on 'Harry Potter' over witchcraft, homosexuality
Can't Rowling just be quiet?
That's the way it works in fiction. Characters tell their creators who they are and what they're going to do, not the other way round. Any novel worth reading "gets away" from the writer, with characters doing and saying things that may be completely contrary to the author's intentions.
At a later point in the Carnegie Hall event, Rowling said, "The Potter books in general are a prolonged argument for tolerance, a prolonged plea for an end to bigotry, and I think it's one of the reasons some people don't like the books."
Anyone who has read the books with pleasure, as I have, knows this to be true. Prejudice runs like an evil spell through the series, with Muggles and wizards looking down on one another, while elves are forced into virtual domestic slavery, and other magical creatures — giants, centaurs — are pushed to the margins of existence by the dominant group. Rowling's satirical intent is clear.