I'm always very mixed on PowerShell as it can be quite useful and it's mature enough in windows that it really does simplify a lot of windows administration tasks to be trivial and can save a ton of time there by having a nice and safe way to avoid working with the windows ui, a goal that everyone should strive for. The verbosity is not lost on me a d k do find it tiring to read scripts, and it's exacerbated when you read a poweshell script written by someone who started with a "real" language and tries to make PowerShell work like those languages.
Windows apps that have PowerShell cmdlets are a boon also to administration also and I'm grateful when the option is there.
My biggest gripe with PowerShell though is that as soon as you get past the "I don't want to click around windows/.net apps", Powershell shows how shallow it is and its quirks affect performance, design, etc. The PowerShell community encourages a lot of practices that end up trapping you in bad design which makes maintenancen and readability of scripts a challenge. (the handling of variables and their scope can be confusing as PowerShell allows for a lot of "cheating" on which data is accessible and the script will work, but it's very hard to tell sometimes the state of the data being worked on and where it came from. Use of += for adding to arrays is fastest to write at first blush, but you end up with awful performance because it copies the array, but your average PowerShell script writer wouldn't know it and ends up wondering why your script struggles outside of simple lab scale tests)
The answer to this is getting into reflection and using .net calls, but to get the right performance and behavior from PowerShell you end up with a good portion of the script being just straight up .net code and at that point I wonder why bother with powershell at all and not just use .net and some faster API to get data from the app or going through wmi to work with windows instead.
You can get complex PowerShell programs for sure. But they're PowerShell only in name, the force powering the program is usually something else that PowerShell only hinders as you need to now deal with PowerShell-isms to make it execute.
So in a sense it's very successful in that I think this is exactly what PowerShell was supposed to do. But I find as I got past short scripts that PowerShell just can't really do anything it does better than another language would. It can't work anywhere near as fast as bash or any other *nix shell can, you can get a lot of depth into windows but mostly through .net calls, and for applications, a good rest API returns the same data, but faster and in a format more useful for other applications. (both program wise and just in terms of concept)
It feels like PowerShelk was (is?) supposed to be a gateway drug for .net. But it's just too easy to get hooked on it and suffer the side effects and never really take that next step to a more mature language, so you get less of high from using it but way more nasty side effects.
(Also the less said about PowerShell ISE the better. I wish MS would just remove it entirely as its difference in behavior from the actual shell wastes so much time in debugging scripts)