Oh, and I forgot to mention, in ball sports when a team is hopelessly behind, they often take their best players out of the game to avoid injury and preserve energy for future games. This also lets the less skilled players get some experience.
Also, even though prolonging the game can be rude, anyone resigning out of respect has done so for the wrong reason. People resign when the position is trivially won, the offense that may come about by continuing is merely a byproduct of the position's trivial nature.
Exactly, you've hit the nail on the head, my friend - play chess in the spirit of cricket. (This obviously might not mean anything to most of you, ha ha)