Minix 2 design pretty much ensured it couldn't be anything more - a lot of early Linux code was about replacing Minix code with something that made it less of a

Minix 2 design pretty much ensured it couldn't be anything more - a lot of early Linux code was about replacing Minix code with something that made it less of a joke, and the experience was fuel for the tanenbaum-linus flamewar (for example, Linus had reentrant, "multithreaded" I/O whereas Minix couldn't due to how it handled I/O). It was only Minix 3 when care was taken to include possibly more complex but important techniques instead of forsaking them for simplicity