Collapse OS, an operating system for after the apocalypse

Collapse OS is an operating system that no-one should ever have to use. It's designed to be useful after worldwide catastrophe destroys human civilization: able to run on junk and easy to work with, assuming a modicum of computer science skill and a copy of the classics.

Winter is coming and Collapse OS aims to soften the blow. It is a Forth operating system and a collection of tools and documentation with a single purpose: preserve the ability to program microcontrollers through civilizational collapse. It is designed to:

Run on minimal and improvised machines.
Interface through improvised means (serial, keyboard, display).
Edit text and binary contents.
Compile assembler source for a wide range of MCUs and CPUs.
Read and write from a wide range of storage devices.
Assemble itself and deploy to another machine.

It runs on homebrew 8-bits, old game consoles and first-gen IBM PC-compatibles, among other things that might be hauled out the ashes.

Without second-guessing the project's ingenious creators, aren't there vastly more later machines lying around? And aren't 16-bit CPUs more practical in general as a technology of last resort?