Not sure I buy that explanation. Looking through this repo, the kernel, drivers, and many core libraries seem to be written from scratch with no dependencies. There are some deps for reading images, and other things outside of kernel/driver function, but this seems mostly written from ground up (A rust based OS could bind to a C/C++ png or sound file library in the same way).
Writing an OS is a fiddly task to say the least. It's one thing to be motivated to create an OS regardless of language (such as this), vs let's create one to showcase a language. It's harder to recruit people for the latter frankly, and having written OS and kernel code, it's fiddly work that more people talk about then actually enjoy doing it over the long haul.
Also in defense of Redox, I think it has far different goals, rather than getting something up and running with interactivity quickly. SkiftOS is much more "toy"/fun hacking vibe.
Writing an OS is a fiddly task to say the least. It's one thing to be motivated to create an OS regardless of language (such as this), vs let's create one to showcase a language. It's harder to recruit people for the latter frankly, and having written OS and kernel code, it's fiddly work that more people talk about then actually enjoy doing it over the long haul.
Also in defense of Redox, I think it has far different goals, rather than getting something up and running with interactivity quickly. SkiftOS is much more "toy"/fun hacking vibe.