Tools (often third party) can be written to perform specific repetitive tasks…
… do you want to spend all your time hunting down, learning, and possibly paying for dozens of “point solution” tools?
A CLI provides a single way to do it all, in a consistent fashion
The Dark Ages of Administration Windows / Server Product Functionality (Services, Configuration Database, etc) Graphical User Interface for Administration (MMC Snap-Ins) COM Objects (DLLs) Command-Line Utilities WMI Provider Scripts (Batch, VBScript, etc.) The Missing Pieces