If I want to remove the airbags from my car and strap a gigantic bomb in there instead, this particular method of doing it makes sense.

I mean, yes, that's true, but it's still a bad idea.

> Balance between security and usability, as usual. If you want more, use pgp, but loose most users.

They could just have a local client. Thunderbird/Outlook/whatever isn't exactly difficult to use, even for non-technical people.