PowerShell & SQL Server are now available on Linux. Both appear to be a direct result of Microsoft trying to be relevant in a Cloud based world. Very quickly, everything shifted to Cloud solutions and running Windows in the cloud is ludicrous. It’s dominated by mostly Linux and why run SQL Server in a Windows virtual machine with all that overhead when you can run a stripped down bare bones Linux with PostgreSQL or MySQL or Oracle or DB2, etc. So they ported SQL Server to Linux so they don’t keep losing customers. PowerShell ported to Linux and Mac allows them to hope you retain Windows systems and now you can manage Mac’s and Linux using PowerShell.
Frankly, there is no good reason to run PowerShell on Linux / Mac. They both can be heavily scripted in a myriad of ways. PowerShell was originally designed to get the kind of scriptability that Linux was capable of doing on Windows