I'd imagine a lot of kernel developers use virtualisation during development so that they can still boot their machine (though they probably aren't running Macs).
I think he was referring to VirtualBox in particular - its kernel modules are endless sources of problems. KVM has its modules in mainline, so it's a more popular choice for kernel development.
Not ARM developers; my workstation reboots every few months, my ARM boards every few minutes :-)
That is, unless you have a qemu port for the SoC in question.
That's also why my host /sbin/reboot is "echo Wrong terminal, you idiot"
