A big part of the allure of Aces High is the continuity of the gaming experience. That continuity is what distinguishes it from traditional first person shooters which generally have very little to none. The rank/score aspect of AH and the 15 minutes of fleeting fame it potentially affords on the web-page is merely symbolic marketing of that continuity.
The beauty of this system is that you can choose to play is such a way as to create continuity for yourself and compare that to others or not, the choice is always yours with no intrinsic penalty for choosing not to do so. I have played many games and in my experience those that are specifically designed to have a draw beyond any single gaming session tend to retain players far better simply by virtue of persistant depth.
The rank structure as it is divided into its four core facets and their constituent components, is a potentially valuable metric, albeit unavoidably flawed, to compare the various aspects of your performance to others and especially yourself from one "camp" to the next. If we remove all artifacts of scoring and rank from the game, we should , by the same logic, reset the maps everyday. After all, a persistant gaming environment that reflects the relative geographic success of the countries is really just a visually tangible form of score keeping. But, doing so would obviously destroy the continuity of experience for the "win the war" types.
So, it is in the best interest of the game to retain, not remove, aspects of continuity. Sure, some people will take the rank/score thing to the extreme in the vain pursuit of public accolades, which could conceivably have a cumulatively negative impact on gameplay. But, I maintain it's necessary to provide an overarching context for the AH gaming experience, removing it would have far worse repercussions.