Machine code varies depending on the platform, and Linux is meant to be distributed to a _ton_ of platforms.
Us web developers figured this out with JS, when IE supported different methods than WebKit and Mozilla. If we can do it, I’m sure you can assemble something that’s universal as well.
All you need to be Turing-complete is `add`, `jne`, and that's pretty much it - and every mainstream instruction set today supports at least those 2 operations: https://en.wikipedia.org/wiki/One_instruction_set_computer
Of course the computer would run terribly - so I hope you're joking there.
A a web-dev analogy, it's like saying we should abandon CSS and use <table>-for-layout because you don't want Internet Explorer 4.0 users to be left out.
I thought RISC was the future?
(Yes, I’m joking)