All your examples are "people who are really serious about hardware" - not software.

A better example is perhaps the British company Acorn, which made computers for a couple of decades but ultimately morphed into the very successful company ARM. (Which originally stood for Acorn RISC Machine.)

Their software was eventually, after the failed Oracle NC project and a number of legal shenanigans, nearly-open-sourced as RISC OS Open, and has a small number of mainly British dedicated followers, but otherwise did not make a huge dent in the universe. https://www.riscosopen.org/