Not all routes between airports are served by an Airway, so any direct routing is a definite bonus.
I've been on a flight where we've taken off out of an airport in Sweden late at night and been given a direct routing to our final approach fix with about 400nm to run.
From a commercial point of view this is ideal, as it saves on fuel/time etc, and I'm sure many tired pilot's who've been there would agree.
I know it doesn't answer yr Q regarding SOP's etc, but there's a practical side to doing it.