Not too surprising, OSX is a common platform for devs who are linux/unix-oriented but want a high-level OS with all the sleek GUIs and mainstream features. OSX is a certified Unix OS, after all, so it tends to speak to emacs users in a way that you won't typically find among the Windows base.
Yes Unix is not Linux, but I see OSX widely used at hackathons and conferences because of its underpinnings.