From Bruce Payette’s book Windows PowerShell in Action:
Why do we care about command-line management and automation? Because it helps to solve the Information Technology professional’s version of the last mile problem. The last mile problem is a classical problem that comes from the telecommunications industry. It goes like this: the telecom industry can effectively amortize its infrastructure costs across all its customers until it gets to the last mile where the service is finally run to an individual location. … In the Information Technology (IT) industry, the last mile problem is figuring out how to manage each IT installation effectively and economically.
To manage this infrastructure you need a toolkit. Why not use the same toolkit for operations that was used for development?
This toolkit cannot merely be the same tools used to develop the overall infrastructure as the level of detail required is too great. Instead, you need a set of tools with a higher level of abstraction.