If someone wants to prolong a game he could have won and give the other players a chance to deny him, that's entirely up to him. I don't see how it can be considered selfish or cheating or imbecelic or being a jerk. At worst it is simply being patronising or triumphalist. I've done it myself, before the new points system was in place, but now there is even more incentive for a player to try and win with 21+ units rather than 18, because he will of course get more points, not just more satisfaction and glory.
If the other players don't like it, then they don't have to play, they can go CD and let someone else take their points. Personally I would try and use the opportunity to maximise my points or change the outcome, but I guess that's just a philosophical difference.
It is an entirely different matter for someone who is clearly about to be eliminated to prolong his survival by delaying orders, making pointless retreats etc, that is just spoiling, and I would be highly critical of anyone who took that route. And indeed, anyone who thought the two situations were comparable.