Well, yes, powershell takes some shortcuts and has the advantage that .NET has a strong object system.
If you were to build it from scratch with the idea of "shared nothing" applications similar to the unix model with text files, it's not that much more difficult with just about any sort of object or message broker. You could easily imagine a world with a dbus based "REPL"/shell, for instance. Or a different approach easily imaginable if you still want to focus on unix-style streams/files between processes would be something like BSON streams (thought it would still have some serialization/deserialization overhead).
If you were to build it from scratch with the idea of "shared nothing" applications similar to the unix model with text files, it's not that much more difficult with just about any sort of object or message broker. You could easily imagine a world with a dbus based "REPL"/shell, for instance. Or a different approach easily imaginable if you still want to focus on unix-style streams/files between processes would be something like BSON streams (thought it would still have some serialization/deserialization overhead).