Without character development I find myself being rather desensitized to just nature of war. 18 stories would mean nothing to me at all. There is just no reason for me to be emotionally involved in any of the stories at all. Furthermore, I feel with each story only lasting 5 minutes even if I had any emotion toward first two or three stories by the end I would have left being bored of it.

With that said this movie would just not been for someone like me. From what @hanshotfirst said about not even knowing the main characters well. I feel your method at least would push the envelope in one direction. When creating something out of the normal experience perhaps 18 stories would create that shock and awe feeling of how brutal and short lived life was on the battlefield. Either way, the movie just didn't do enough to meet either of these types of views expectations.