I haven't used PowerShell (since I don't use Windows), but when using the Unix shell interactively every so often I find myself in a situation where the data is too complex for a shell command to be able to process it, or else running into some corner case of missing functionality. Usually I end up piping into python -c, but that ends up pretty gross... if PowerShell isn't the answer, what is?
I wonder how far you could get by sort of plopping PowerShell onto the Unix shell and supporting both structured and text data.
(Incidentally, one such corner case is summing a list of numbers - this sounds like it should be a short command, but actually requires a complicated command line using awk.)
Which is IMHO the best part about unix shell and the worst about PowerShell: being pure text, unix shell allows for very loose definition of the interface between the program and outside, allowing to connect stuff in creative ways with minimal plumbing; whereas PowerShell makes this interface definition quite stringent by comparison, hence needing theoretically less plumbing (at least for simple tasks) but requiring far more design in the interface, restricting connectivity which in turns generates more mediation and plumbing to connect foreign elements.
In short unix shell may seem archaic but its loose binding makes it very powerful and quick to solve problems, while PowerShell is, well, a chore.