> There is nothing in NT kernel that forces a certain UI toolset
Unfortunately, Windows the OS and the NT kernel are not completely independent - you can’t really run one without the other.
> we had to replace X
We did so because we wanted to continue to run apps made for it. The fact it was done without any change to the Linux kernel is precisely because the graphical environment is just another process running on top of the OS, and it’s perfectly fine to run Linux without X.
Unfortunately, Windows the OS and the NT kernel are not completely independent - you can’t really run one without the other.
> we had to replace X
We did so because we wanted to continue to run apps made for it. The fact it was done without any change to the Linux kernel is precisely because the graphical environment is just another process running on top of the OS, and it’s perfectly fine to run Linux without X.