AlliumCepa: here is a dialog with one of my opponents after such game:
Me: Thank you for your professional resignation.
Opponent: Excuse me,
was there anything wrong with that?
Me: On the contrary. It showed that you value my time, you are smart enough to predict when a game is lost, you can swallow your pride and terminate the pointless dragging. You do not need my painful and often fruitless explanation why would be reasonable to resign. I respect you for this.