That's my problem with PowerShell. No matter how good it may be, I don't really feel like relearning everything just to accomplish the same things, only on Windows instead.
I'm right there with you not wanting to learn a new shell, however PS is written against the .NET Windows API. The new stuff you'd have to learn would be Windows specific, sort of like learning AppleScript. Also, PS has traditional unix shell commands built in now, like grep and ls.
I like relearning. I don't have much use for re-learning... I'd rather learn to do something new. The "to accomplish the same things, only on Windows instead" is the crucial qualifier. I'd rather spend my time, I don't know - learning to configure nginx or doing Haskell tutorials than learn someone's proprietary shell, given that shells aren't particularly exciting and I already know enough about the shells that every other platform offers to be satisifed.