Consider this tho - even on a PC, if a firmware (ie: bios) update fails, your motherboard will be bricked and you will need to get it replaced or sent in for service.
If the OS update failed and you couldn't get back into the OS to fix it, as a last resort you can always reinstall the OS, but since what failed appears to be the firmware update they are following the best course getting you to send it in (or bring it in) for repair/replace.
Although on some desktop pcs that you can have easy access to the motherboard, you might have an additional option (if the flash chip is removable and you can find another one for your make/model of mobo, although for most non-techies, they would rather just send it in for repair) laptops (or laptops setup to act as desktops) are extremely difficult to service if the part is not accessible through the limited access doors so you'd be stuck sending it in (and not all laptops have removable bios chips due to the amount of space in the case).
Certain things are just the same across systems, whether it's an older Apple using Open Firmware, Sun using Open Firmware or whatever they use now, PC BIOS, etc. if a flash to the hardware fails, it will tend to brick the system.
