Re: "On Linux we’re just another shell"
@P. Lee - "Who's going to rely on that having a future? Unix people won't - they won't trust powershell to be on all unix systems."
Not just "won't" rely on it, but rather "can't" rely on it. Linux runs on a far greater range of hardware than MS Windows. As a result, core parts of the operating system have to work on hardware and in situations and under constraints that people at Microsoft have never heard of, let alone test or support. Therefore, PowerShell can't be a core dependency for most serious distros. It can only be a non-core optional package, which few people will bother to install.
@P. Lee - "MS control many of the apps running on Windows servers and they can powershell-ise them. What happens when you don't control the applications? "
It will only ever be of interest to companies, such as Microsoft, who already have "powershell-ised" applications that they wish to port to Linux from Windows. These will typically be proprietary "enterprise" applications. If you don't use that application, then there's no reason to install PowerShell.
In other words, don't think of PowerShell as something you would install for its own sake. Rather, it's just something that would get pulled in along with some other application.