In XPP, a mouse click in an empty part of a page automatically takes the cursor to the very top of the open division. This becomes very problematic when you have a large document open, and you click in the wrong spot.
Other word processing applications (Word, InDesign, etc.) will move the cursor to the nearest text, or at least to the line horizontal to the location the mouse was clicked.
I understand that those who navigate primarily through the keyboard will not experience this behavior, but I would imagine that many users might prefer to navigate with the mouse, like myself.