I have always wondered that to. Our pastor had told us that times have changed and wearing colors to grieve was to help them to heal.
I think that some symbol is needed so people can move through their community with others aware that they need a little extra consideration during this period. It does not necessarily have to be wearing black, just something that signifies loss. Let's face it, when you lose a close family member or friend it can really throw your head space and even the smallest things in life can become overwhelming, like shopping for groceries, banking, etc..something that signifies grief would allow others to let these people move through with a minimum of fuss and hassle.
We allow for the physically handicapped but seem to ignore when we are emotionally challenged.
That depends on what society and culture you're in. From WWI to WWII in the western countries it was made socially unacceptable due to the fact that so many families were wearing black. In middle-eastern countries, as well as slavic, black is still worn and widows will wear that color for the rest of their lives.
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.