Well it is not actually that much ARM, Acron RISC machines is just delivering the virtual design for CPUs. They do not actually make hardware. They leave it to the various chipmakers and it's probably also up to them or, better up to the "BIOS"/UEFI writers to implement sh!t. The problem is that a lot of devices use ARM tech, especially small mobile things like (smart)phones, tablets and small netbooks. And if they have "hardwired" non-optional secure boot that IS an issue.
Either way I do not want or need secure boot on any platform. It sucks. It's TCPA/TPM name it as you want and thus it is utter crap and always endangering customer's rights and freedom. It does NOT give the user any security enhancement. It is just an instrument to control the user.
Maybe I sound like rms now but that is fine cause in that matter he's usually just right.
Stop TCPA, stupid software patents and corrupt politicians!