Actually, I think this has at least as much to do with different game cultures as it has to do with nationalities. In chess, you will sometimes find yourself in a position where:

- you know you're lost
- you know your opponent has the skill to win the game
- but it will still take some 30-40 moves for them to do so.

I suppose that's why experienced chess players have developed this etiquette that you resign when you know you haven't got a chance (unless there's only a few moves left, in which case your opponent might actually be happy to mate you!). I've played chess with people from all over the world on many different sites, and I've never noticed that people from the US were any different in this regard.

The problem, I think, is when people take the game etiquette that they've learned at one game and apply it to a different game and expect it to be universally valid. Which is bound to happen now and then on a site like this. The solution, of course, is to try to tell yourself that whatever your opponent does, he probably means no harm... live and let live... and Fencer, please don't add any more achievements that requires the game to be played out to the end ;-)