- You can't even run your own scripts without performing the Set-ExecutionPolicy ceremony first or signing your scripts.
- It's way too verbose.
- It's a strange bird that next to nobody uses, so there's zero motivation to learn it.
- It's not "old reliable". You can't depend on it working due to the first point and also due to the fact that they're still working on it and even in 2016 they broke some PowerShell stuff with updates that needed to be uninstalled (KB3176934).