***The essence of moral evil is "my will be done."***
It also gives children a taste for "spiritual power".
I have commented several times on these two threads that HP books entice children with the fantasy of having wonderful powers to control others with magic. Others including the natural world, and other people and animals. This is exactly the foundation of "black magic". People believing or not believing such powers existence doens't make any difference - the seed of the matter is the HP books strongly and seductively encourage the desire to be Lord, and to achieve any means to do it, including the glittery world of magic.
Control of others, not control of self, which is the real duty and objective of life.