Suppose a novel was written for children which said there is 'good' fascism as well as 'bad' fascism, and that we must use 'good' fascism in order to battle bad fascism.
Or suppose there was children's book which talked of 'good' fornication or 'good' hallucinogenic drugs or 'good' torture.
Christians feel just as uncomfortable with a message that says that there is 'good' witchcraft. The Bible teaches that all witchcraft is inherently evil. There's no 'but' about it. That's what the Bible teaches.
If you don't believe in the Bible, that's fine. But articles like this are clearly not written to get secular humanists to let their children read Harry Potter. They're intended to get Bible-believing Christians to let down their guard and permit -- if not encourage -- their children to read Harry Potter.
Perfect analogy. Another one. What if one day Harry found out that his father was a good Grand Dragon who defeated another bad Grand Dragon, and that he himself was a member of the KKK; who then went on many exciting misadventures with his KKK buddies.
I don't think it's the Christians that will have a problem separating fantasy from reality. I believe it's those who don't have the Christian background, don't have the Mom or Dad to read to them. It's the one who are without God who need the escape that fantasy can bring them and cause them to begin to blur the line between fantasy and reality.