The essay "Free Your Technical Aesthetic from the 1970s" [1] by James Hague is appropriate here. See also The UNIX-HATERS Handbook; much of it is outdated, but I think some of it is still relevant, particularly the part on the shortcomings of pipelines.
I think it's unfortunate that even if a good open-source PowerShell clone is developed (or PowerShell itself is open-sourced), it will probably never gain widespread acceptance outside of Microsoft shops. Tribalism so often trumps actual merit. But if someone did a PowerShell-like thing on top of Node.js, I could see that taking off, particularly if it were integrated with the Atom editor and its package manager.