Well, at least for OSX, you can technically run VMs, I've been doing it for a few years now (I needed one to troubleshoot CMake issues specific to OSX).

For iOS, I would grant that.

One last point is that OS X is partially Open Source (at least Darwin is) even if in actuality, nobody really cares about it (like building something on top of Darwin).

In the end, neither of MS or Apple is my preferred choice anyway. I much prefer an OS I roughly understand (at least to some degree) each pieces and on wihch I could generally troubleshoot things (Linux, *BSD), even if I do acknowledge I'm far from your typical user being a "dev/sysadmin/devops/whatever it's called these days".