Because he doesn't want to ruin his image of a "man who brought peace into the world," sort of like a glorified Gandhi, or whomever. It might ruin the atmosphere of his Presidential Library. Obama mainly cares about his own image, like Kookie Byrnes combing his hair in the mirror.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.