Clearly this would only affect casual users, but I an assure you that most users are not being *that* careful with their wallets.  They may have a backup on multiple different drives but what good is a backup if the auto-update can patch the bitcoin client and transfer your funds the next time you unlock it?

The point of this post was that your wallet and password is only as secure as the software you allow on to your system.  The solution is an open source hardware wallet that is never updated, never has network connectivity, generates all keys, and for which there is no means to get the keys off of the device.  

Then this wallet must be made as easy to use as possible.    Ideally the entire wallet and hardware system is open source.

Users should never have more than the cash they normally carry with them backed by any private key that has ever existed on a networked computer.  

Note when I said exe it was short for executable which linux certainly has.