He's literally complaining that apple's firmware does not init the hardware properly. If he's using the legacy BIOS boot, that's a fair assessment of that mode, but it's still not the standard way to boot the computer.
Many open source OS projects have core developers on non-x86/amd64 platforms so as to find errors, x86isms, and other code quality issues reveled by fundamental differences in the underlying architectures.
That's interesting. Pitty I couldn't find a quote in my brief search. I'll try to find that interview later.
The bit that really caught my attention was this: "(...) Torvalds, who briefly moved Linux kernel development to GitHub last September following a security breach at its old home."
https://lkml.org/lkml/2012/1/14/4