A bank is not equivalent to your home. You may note that banks generally lock up their physical money behind very sophisticated security systems (relative to other homes/businesses). They deal with a different level of threat, and respond accordingly. Even then, they don't try to safeguard against someone physically demolishing the building, because there's only so much they can do, and at the point someone is willing to go that far, the chance they will complete the theft without being noticed and tracked is virtually non-existent.