In Mage: the Awakening, casting obviously vulgar magic that can't be explained mundanely causes paradox. This sort of damages the universe and can cascade into more impossible things happening, like shadows not being where they should. A sleeper observing something that he considers impossible clearly has pretty big effects on a universe level.
How does this work with the other World of Darkness character types?
Vampires can do all sorts of impossible things, but they never have to worry about damaging the universe; they just worry about the Masquerade, which is just a social construct.
Changelings have to follow their Oaths, but they can use impossible without any issue at all. For example, Wayfarer magic allows them to teleport instantly.
I'm sure there are more examples, I just don't know them.
So, why is it no problem for every other character archetype to do things that "mundane" people would find impossible, but for a mage this can really screw up reality?
(Note that I don't know much about World of Darkness, but I have played a few Mage games. I am interested more specifically in new WoD.)