Much classical photo-journalism has been done in black & white. This is quite a change from the way our eyes see the world.
I guess that I really do not care too much if the meaning of the photo is not changed.
One of the photo manipulations that bothered me in the past was the photo taken by Arnold Newman of Krupp for a book cover where he used lighting to give Krupp a very sinister look. This would be OK with me if he has first said to Krupp "I am going to make you look sinister". The Krupp family has much to be ashamed of in their WWII behavior. I feel no kinship with them.