ok, name it "motivation" instead of Business case.
for GNU Emacs, the motivation is completely clear: it's a tool for developers, and some of those developers contribute and make it better for everyone.
For ReactOS... ok, someone seems to have a motivation, but that's completely beyond my understanding :)
OK, I read it and I think you've a point.
> Without a business case, any exciting project would eventually disappear.
I don't understand what you're arguing here. What is the `business case' for GNU Emacs?