Actually there are a business cases where such a script is quite usefull. I work for a global corporation with over 700 instances of SQL Server spread across the globe. We are less than 20 SQL DBAs.

We don't like turning on xp_cmdshell on all our servers as this is a security problem. But our backup script needs to create subdirectories, create a log file for each day, move those log files to a central logging server, archive old log files on that server, delete even older log files, delete old backups, etc.

As you can see, pure T-SQL without xp_cmdshell will not help. A stored procedure written in .NET can. But I don't like loading assemblies on each servers either. And if I have to run a T-SQL script from a batch file which does all the work for me, then why not use PS? It's much more comfortable to write such operations in PS than in standard DOS batches.