1) Big corporations don't like to overspend on PC hardware and can have great deals with anyone but Apple.
2) A company that work mostly on Windows platform (.Net, MSSql)
4) As weird as it sound some people might actually not like OSX.
On the other hand, I REALLY like the idea of an app and all its dependencies being installed all in one folder. That REALLY needs to happen everywhere. This would make migration between installs SO much easier, and would eliminate DLL hell (or shared library hell in the case of linux).
Just my 2cents
I also dont like the dock, i like to have a taskbar with the open windows on each of my monitors which is no problem in Windows and Linux. I dont like the Menubar stuck on the main monitor.
As a web developer i really like the unix base of OSX for different reaons though and i need to use some software for game dev (Unity3D) which isnt available on Linux.
But i thought about running Windows for game dev/office stuff and Linux in a VM for web development.
Oh yes. I wouldn't take a job if they offer Apple only choices.