I can't believe that you are downplaying the severity of this, arguing about what clobber means, and going (again) into the technical details of how grub works.
It is the user experience that matters, not the technical details. Please think about the non-technical end-users. For them, their machine is bricked. They might not even know that they can boot the machine with the usb drive in it. Even if they knew, this is not an acceptable proposition.
I can't believe that you are downplaying the severity of this, arguing about what clobber means, and going (again) into the technical details of how grub works.
It is the user experience that matters, not the technical details. Please think about the non-technical end-users. For them, their machine is bricked. They might not even know that they can boot the machine with the usb drive in it. Even if they knew, this is not an acceptable proposition.
Even if the technical help is available for them, in the form of a friend, a colleague, a local repair lab or even a google search, how many hours or days, work-time and money will they lose before their machine is back to normal? (https:/ /bugs.launchpad .net/ubuntu/ +source/ grub-efi- amd64-signed/ +bug/1396379/ comments/ 41)