What evidence do you have that the majority of developers are on Unix? Just web devs or all devs?
I doubt that it's true in either case. IT departments around the world employ programmers to make all sorts of business apps including internet/intranet web apps. Even some very small companies have custom apps to do business and the vast majority of businesses are using Windows.
And this is a great development - it means for future enterprise projects, Node will become a more realistic choice, because it means that using Node on a project doesn't require orgs to build entirely new infrastructure to support * nix deployments or dev environments.
For the most part, npm packages work fine on both Windows and nix platforms. However, it is pretty clear that most are developed on, and have fewest problems with, nix. I believe that is due to the massive popularity of Macs with the JavaScript-focused web dev crowd.
I doubt that it's true in either case. IT departments around the world employ programmers to make all sorts of business apps including internet/intranet web apps. Even some very small companies have custom apps to do business and the vast majority of businesses are using Windows.