What completely amazes me is how OS X doesn't warn users to backup that block, constantly, until it's done.

I use Arch, which is not beginner friendly, but the wiki states this in a big, red banner. I'd expect an end-user friendly OS to do the same once the password is set for the first time, and over and over again until the backup has been made.

Does Apple actually enjoy leaving all the user's data to chance?