Or we could ask why doesn't the game include "Rape the German Civilians" mode for the Russians or the "Roundup the Jews" mode for the Germans?
Certain things that happened during the war had nothing to do with the average battalion level firefight, and have no place in the game. To allow players to commit those atrocities, even in simulation, is to trivialize the real suffering those events caused.
On the other hand the complete lack of sheep and cows is a total disappointment. I can suspend only so much disbelief.