> From an administration standpoint they are much easier to setup and use thanks to their GUIs. Windows is very standardized and has very good management tools and interfaces.

Having managed both, I have to disagree very strongly. A GUI works fine when you want to manage one machine (although it's kind of a pain in comparison to SSH), but when you want to manage dozens, you need sharper knives. The tools available for automating devops (chef, puppet, etc.) are very oriented towards UNIX-based OSes. We have around 70 Linux machines in our production system today, and if I had to manage them through RDP and GUIs, I'd probably quit and become an alpaca farmer.