Yeah, using the Windows 2012 GUI is madness. I love my job, but the metro interface in a server environment (even when "properly" set up to remove as much of it as possible) was the first time in years when I dreaded having to RDP into a machine to work with it. I am not a command-line-Linux guy at all, but for 2012 Powershell does make everything far less frustrating for me.
There are many ways to say the same thing. Some are inflammatory and - yes - immature. Some are constructive or just expressing an opinion.
I'm pretty sure your message could have been conveyed better, e.g., "I prefer managing the system using PowerShell and think I can be very productive with it" rather than saying "Using the GUI is madness".