I think you havent read the books. The HP series isnt a guideline or reference manual for witchcraft and wizardry. Witchcraft and wizardry are nothing more than plot devices in the books. The stories could easily take place at soccer camp, but theyd be far less inventive. There are no references to summoning dark powers, demons, etc. The kids at Hogwarts are engaged in studying a technology for making things happen. Looking at it another way, Hogwarts could be looked at as an engineering school