To me I personally think the score is more important than the killscreen. I would rather have a million point game with no killscreen over an 850,000 point with a killscreen. Of course the game I am best at is DK3, and that is the one where there is no real killscreen. I get the beauty of having to become more, and more technical with your game because there is a killscreen, but the killscreen itself is not the end all, and be all of the game.
The killscreen to me is the cherry on top on the banana split sundae. Even without the cherry the banana split sundae is still awesome!