You and I agree that VRC has value, so we agree to the exchange, I send you VRC, you ship me gold coins.
A bad man steals many VRC from MintPal. Blockchain gets rolled back. I get my VRC back.
*But I Still Have Your Gold.*
You win the arguments fight, end of discussion!
Uh, no. If you have the gold and you gave another man the VRC for it, then HE gets his VRC back while you have the gold. So everything is still even.