I think the syscall translation part is an irrelevant hack, seems silly to act like that is what makes the project more useful because it does not guarantee performance, compatibility or stability.
The syscall translation makes it more useful than the previous UNIX subsystem, because it means it can near-perfectly emulate a popular POSIX-like system (Linux), and thus be compatible with most of its software, rather than being its own eccentric platform that existing POSIX software must first be ported to.
I feel that you miss the point of WSL. Bash and coreutils have worked on Windows for years. In fact, they ship with git so most developers have had them for years.
The point is compatibility much more than CLI UX. The ability to run that nodejs or Python project even though one of the 1352 subsubsubdependencies has a bug on Windows.
There are Linux distributions which contain almost no GNU software, e.g. Alpine Linux which is built around musl libc and busybox: https://alpinelinux.org/about/
