"Or perhaps a specialized variant of ReactOS with that focus in mind."

Trouble is there's never been enough interest in ReactOS to get it to the point where it's stable let alone warrant fancy extras. (After three decades of trying to clone the basics and failing is proof enough.)

In short, developers see it as a dead end. Why there's so little interest I've never fully understood, but it's fact.

If it were actually stable and usable as a basic operating system it could be used for lots of offline stuff but it's not—even at this point. If it were useable I'd readily adopt it to use offline (I've tried many times and failed).

Another point, this lack of interest shows up on ReactOS's website; there's so little new news and info the site may as well be dead.