mac partition failed could not unmount disk

OK I tried just a standard Apple 500 GB drive. I sent emails out to all my customers with SSHD drives not to upgrade a couple of months ago. I’ve already replaced about a dozen drives out of my pocket because of this. All are now non-functioning because of High Sierra updates and I can’t fix them. I have five machines MBP 2011-12 on my bench right now that were upgraded with Seagate SSHD drives. If I run into someone who helped write High Sierra or Mojave and included these obstacles to make older Macs obsolete, is it Justifiable Homicide if I strangle them with my bare hands? Or should,I just carve an Apple logo into their foreheads? If I install a partition with Disk Utilities I get the same thing. “You may not install this volume because the computer is missing a firmware partition.”

When trying to install internally I get the popup, Mojave installs just fine on an external drive, the when put into the machine it destroys the drive to the point of being unable to even format it or even see it.

Mac partition failed could not unmount disk