Why is one thing condemned and another accepted?

I was reminded of an incident involving a woman I worked with a few years ago. A group of us were in the break room and somehow the subject of Harry Potter came up. One woman vehemently attested she'd never let her daughter read the books since magic is evil. I spoke up at that point asking if fairy tales were acceptable. Of course they were. That makes no sense, if you really look they are some of the worst things imaginable. Hansel and Gretel for instance. We have abandonment, cannibalism and murder all in a story acceptable for children. Not to mention the gruesome things in Cinderella. And what about Santa Clause. Magic is the only way to explain him, and in fact is how he's explained to children. I won't even get into the debate between magic vs. miracles.