Just as it's easy to forget other people's suffering when you have no skin in the game. 

A million Americans on both sides lost their lives in the Civil War. Regardless of the motives that the war was fought over, it was a cataclysmic event. Would you likewise deny Germans war memorials to any of the dead, because the Nazis were in power?

German war memorials: http://www.thirdreichruins.com/memorials.htm