Just based off of the commission's and trade volume, you know major exchange's have much more than this amount already, what is the need to prove what we already know? It doesn't matter what amount some exchange has of there own coin, it doesn't mean they would use it to protect there users. Such a proof would only give people a false sense of security.

They could spend there time working on this, and potentially opening up more holes in there system, or exchanges can spend the time increasing there security so they don't end up like mtgox. Without gox as the target im sure these other large exchanges are next.