I generally fly for the reasons Lazs stated. To me that is fun and challenging. However, I could easily get more into winning the war if it involved a real challenge.
I played JR High and high school football and tremendously enjoyed the competition and winnning the game. You had even sides, and you won or lost based on solid teamwork, individual skills and leadership both on the field and from the coaches. In high school we were typically 500 for the season. But, each of those wins meant something, and even the losses were O.K. as long as you put up a good fight.
In here, "winning" seems to be mostly about grossly uneven numbers and a minimal amount of organizational skill to make sure bubba brought the goon. I get no sense of accomplishment in this style of game play. It would be like winning every game in a football season, but doing so with an extra 5 players on the field every game. Who cares.
[edit: there are certainly exceptions to the rule, but IMO 75 percent of the "war winning" centers on this gameplay format today.]
Charon