The past has shown that everyone, even persons who run e-wallets and currency exchanges, severely underestimates the amount of security such an endeavour requires.
There's a hundred questions you should ask anyone who asks you to keep care of bitcoin. How large is the hot wallet? How is the offline wallet stored? Where's the source code? What hardware does the service run on? Who are you? What will you do when someone steals your hot wallet? What monitors do you run to make sure the books add up?
So, nice idea, but please make sure this is actually going to be safe.
(BTW there seems to be a way to escrow bitcoin where a third party decides if the transaction should pass, but that third party never gains access to the bitcoin themselves, I haven't read the details of it, but that would seem perfect for this sort of thing)
But perhaps it would be more grand if that expensive and bureaucratic third party could just be avoided with a smart technical solution :)
A bank account of course solves all those things, but because of the nature of bitcoin it's rather hard if not impossible to realize the financial system we know as banking using Bitcoin instead of government controlled currencies.
So if he was indeed talking about a bank account, then it was a sneer towards Bitcoin itself, and he'd be quite right, the banking system solves this problem very well.
I still think the three party transaction system would be preferable even to banking, if it can be done.
Instead of trying to improve on the monetary policies and regulations that exists around the world, bitcoin simply tries to replace them and leave nothing in their place. It is like going from the current US government to anarchy. There are a lot of things that can and should be improved in the old system, but that doesn't mean we should throw it completely out and have nothing to replace it.
update: fixed a mistake (online to offline)