Hogwarts pooled all the ambitious and clever people in Slytherin. The people who understand that it’s not cheating if you’re not caught and that rules are meant to be broken. The people who can see the line from point A to point B, when no one else wants to see the line.
These are all valuable traits. Wizards are few in number. They built an entire secret society not because they thought they were better than muggles, that’s just the lie they tell themselves, but because they didn’t stand a chance against the muggles armed with sharp sticks. And now the muggles have guns.
The Slytherins are the people who you want on your side when shit really hits the fan. Because they’re the ones who get shit done.
Doctor Strange sacrifices the life of one man to save the universe. A Gryffindor would have tried to sacrifice themselves. A Ravenclaw would have tried to find another way. A Hufflepuff would have never made the call. This is a Slytherin move.
There are bad kids in the other houses. And there are good kids in Slytherin. But there are more dark wizards from Slytherin than from any other house because they’re the people who refuse to be limited by the box. And sometimes that’s a bad thing.