basicly i think because most people only dominating the Windows Part of IT world. True there`s networking but i think most of my friend taking IT only well knew much mostly Windows Stuff. and dat`s it.

The lack of embracement in Unix and Linux OS definitely give a problem here.
I have a friend of mine making opengl program for the X windows System. The only reason he is hired because he`s the only one in the candidates that can use Unix huhu.