That is fair but in my experience most devs are targeting linux servers not BSD(or any other flavour) which is helped by OSX. If OSX was linux derived it would suit them just as well.
edit: I suppose I should also note the vast majority of people developing on mac books (in my experience anyway) are actually targeting chrome.
> Turns out, an operating system is more than just a kernel with some userspace crap tacked on top, unlike what Linux distros tend to be.
This is also my opinion of OSX, let's not pretend that the userland mess is the most beautiful part of OSX.
Apple has great kernel and driver engineering for sure but once you go the stack above, it's ducktape upon ducktape and you better not upgrade your OS too quickly before they fix the next pile they've just added.
Heterogeneity is the feature. The Linux ecosystem is better off for it (systemd, Wayland, dconf, epoll, inotify are all based on ideas that were in OS X first) and not being beholden to Linux is a competitive advantage for Apple everyone wins.
edit: I suppose I should also note the vast majority of people developing on mac books (in my experience anyway) are actually targeting chrome.