Why is this being downvoted? What am I supposed to say? I'd say the same thing as if they were hacked and malware stole their credit card. Computers aren't magic; there is an expectation that you know what you're doing with them. If you don't know how to secure a wallet, don't use Bitcoins. If you don't know how to keep malware from stealing your credit card, don't download virus-infested porn or go buy an iDevice.
I'm assuming I was being seen as cynical but as with "the command line" and "Git", I'm not sure what people want. A magic, easy, secure solution? Sure, we'll just ignore the fact that identity management, authentication and security aren't complex issues that are still evolving today.
If we're just rehashing "Centralized currency is easier to use" then by all means, whatever, yes, Bitcoins are currently harder to use than cash both because they're more complicated and because there is almost no infrastructure to support their use. But frankly, that's really a completely separate issue from whether or not they can be used securely. I can give you tens of security and usability problems that cash has day-to-day that Bitcoins are unaffected by.