> You shouldn't spend your own effort; you should make it clear that you're open to users of such systems contributing.
In practice you can't really draw a line between those two things.
I don't know the end result, but I remember a discussion of how implementing parts of Git in Rust would be a problem because NonStop, a currently supported platform, has no Rust support. Of course the sane response would be "screw NonStop then", but having accepted contributions to make NonStop a supported platform that isn't an easy path to take.
That is absolutely true but exotic platforms are also fun to investigate and you can learn a lot. So I'd say you shouldn't spend your own effort if you don't want to but I am glad fractalfir did and I am looking forward to the his RustWeekNL presentation.
That's how GCC became so dominant - there were people already using all sorts of Unixen and they wanted a compiler, so they made it work.