When is it beneficial for the Active Object to be unselected? Being relatively new to Blender I'm trying to understand the Active Object vs Selected Object paradigm. 

When selecting an object I'd assume you'd always want the last object you selected to be the Active Object. But I've noticed you can create situations where a single object is Active, but not Selected. Or Selected, but not Active. You could also have a group of Selected objects on the left and a single unselected Active object on the right, for example.

Are there situations in Blender where having the Active object unselected, or an inactive object Selected, would be beneficial or even necessary?
One situation that comes in my mind is when you have the pivot center set to "Active Element". 

I often use this to rotate the selected objects around the active object without rotating the active object itself. To achieve this I deselect the active object before I perform the rotation while it's still active.

(boah... sounds more complicated than it is :))