Killing in games is just conflict resolution at it's simplest. An obstacle stands in the way of a achieving an objective, so superior force is used to remove it. However if you know "The art of war" Sun Tsu you understand that these victories are not a superior strategy. Ideal strategy "Takes whole" or achieves its victory not in conflict with its obstacles but using them as advantages.
This thread seems focused on where combat games can go to escape the mindless killing. This is my suggestion. Look to the art of war to make war games a little higher art. Many seem to blame players for the difficulty of designing war games more creatively, but the success of creativity doesn't demand the audience be different. It teaches the audience how to look at the art of creative game design differently. You don't need creative game ideas you need creative ways of introducing the ideas to the gamers.
If the objective of the game is to, move from point A to point B without enemy X stopping you. The player needs to know first the basics, moving between A and B. The threat, how enemy X stops the player. The conflict resolution, the methods reaching point B using X to you advantage. The variety of options for the player to discover on their own (to achieve this objective with more efficiency) are the achievements that make the game fun. Don't blame the player for not being able to expand on this structure, look to be creative and innovative in introducing these new structures to best entertain your gamers.