If your sole argument is that .NET has weak integration on platforms for which version 1.0 of the core runtime was only released two months ago, then I don't really have anything to add. Of course it's going to have a weaker integration than a tool set that has existed and been developed together for decades.
However, your original argument was more along the lines of PowerShell being a walled-garden of cmdlets. Which is patently wrong -- it works with any .NET code. It also works with the standardized structured text formats of CSV, JSON, and XML.
It does not currently have tools to work with the two-dimensional text structures typically found on *nix machines, because until this week it was not even available in those environments. We might very well see creation of tools to ease this process.
