While I hate the gradual death of general purpose computing as much as the next nerd, this bug in particular has nothing to do with it.
On a PC, the situation is different. At worst, with bad GPU drivers, you can still fallback to good old 640x480 VGA, or a slightly better generic unaccelerated VESA framebuffer, and be able to troubleshoot from there.
I'm undermining my own counterargument... On a PC, a bad BIOS flash is recoverable. Some have two BIOSes - like on video cards. Some have a recovery mode via a USB stick. And attaching a programmer to the SPI flash is also a viable recovery method...
Maybe he doesn't think any of the mac firmware environment is really that different from a general purpose computer?
Ok, I don't know what the counterarguments are. ¯\_(ツ)_/¯