Given that some Marauder delusions are contagious, that causes the Wizarding World to make a lot more sense. The four of them could have been Order of Hermes students frustrated by the difficulty/complexity of doing things the right way, so retreated into a shared fantasy where magic is a matter of pointing a stick at things and uttering pseudo-Latin gibberish. The shared delusion has been spreading ever since and all Hogwarts students are being indoctrinated into the madness.
“I really hope I’m behind this convoluted mess; at least that way I’ll be able to get revenge by doing this to myself. I won’t even have to feel bad because it’ll be all my fault.” - Harry Potter, The Master of Death by Ryuugi.