It's symptomatic of all online wallets with instant automatic withdraw capabilities. Not just limited to Bitcoin. Online wallets, that transfer real money to external third parties (not just an internal credit transfer like Paypal or credit cards, which don't actually remit the money to unverified receivers outside of their system for 30 to 60 days) will all have this problem.
It's not at all required though. You can easily build per-user wallets that employ multisig, where the user has to actually authorise each transfer. If the service shuts down (or gets seized) you just publish your key and users can withdraw their own cash.
Why would I need an online wallet though. I mean that's what I use my bank for. They even give me a small amount of interest for the money I keep there. Anything not in my bank is in a real wallet in my back pocket.
