Re: No POSIX
>>"POSIX is an open set of industry standards, designed to improve interoperability. Windows is a closed Microsoft 'standard'. It would be easier for Microsoft to fully implement POSIX compliance than Linux implement Windows compliance. "
POSIX was designed to bring some consistency to UNIX operating systems and its family. I'm not even sure much of it applies to Windows.
>>"and it's even less common for Windows to have a halfway acceptable terminal app installed"
ISE comes as standard on WIndows 7 and 8. It's actually very nice. Also includes a built in debugger.
http://blog.soporteti.net/wp-content/uploads/2013/06/powershell_ise_gui.png
>>"Windows still can't be 100% configured / controlled from the command line"
Can you give an example of something that can't be managed in Windows via Powershell? Especially, as you're using this as a comparator to GNU/Linux, something that can be done on that other system.