There could be another reason for the supers powers: it's aPixar film. There was no WW2 attempt to create people with powers. It's just people with magic, like Elsa from Frozen. And when you take the Pixar theory into the mix, this would explain why people are blase with people with powers, as magic and other powers are a common occurrence in their world.
On the grounds that, "They have superpowers because it's a movie," is not fridge anything.
Removed this:
On the grounds that, "They have superpowers because it's a movie," is not fridge anything.