With intel ME next to it, it seems like asking for a metal door, with special key shapes the competition has a hard time to produce, but on a wall you know you can break with a hammer.

The current state of computing is less and less about being pro people, and more and more about pro big players.

>I think Microsoft was right to push for Secure Boot / bootloader signing

Signing by whom? The OEM of course because giving the key to the user would be unacceptably user-friendly for microsoft.

>I don't think UEFI was the right horse to put money behind. It's a complicated hot mess and the most visible innovation has been to use UEFI identifiers for DRM within web browsers. Yay.

UEFI was done that way for a reason. Don't underestimate Microsoft's influence on other companies. Same thing with big web companies pushing "open" standards that only they have the manpower to comply with.