If you have to be a security expert to own more than a few dollars worth of bitcoins, the project has effectively failed already.
Why?
It's true that key management and security are not as good as they could be in the official client, but that doesn't mean the project has failed, merely that the client needs to be improved.
Improving the wallet security is priority #1 of the dev team at the moment.
Note that no one of the developers expected it to get this big this fast. Six months ago, no one would even bother stealing bitcoins as they were not more than a toy curiousity. Now very serious amounts of money are represented.
Why?
It's true that key management and security are not as good as they could be in the official client, but that doesn't mean the project has failed, merely that the client needs to be improved.