Because they have a Bias presupposition, so no matter what proof is presented they will deny it.
Look l have seen Photographic evidence that the world used to be Color sepia 130 years ago, Obviously a PolyChromatic entity made the colours the we can see today.
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.