I'm only guessing here but if you are talking about page views, the statistics might be assigned to each page separately and added up to create a total sum. When you delete a hub, the views of this hub also disappear as they belonged to it. As the result your total goes down.It's the way I would see it, but don't rely on it as I have no insights into the way it's handled by HubPages admins.
If it's no longer valid, then you should have changed it and republished. You aren't being penalized for deleting the material, but why should you keep the views of a hub that no longer exists? They were deleted in accordance with the deleted hub.
You get the choice of republishing or keeping it unpublished, but if you delete it, the views go too.
Ask Hubpages......You can contact them anytime and ask them your questions. It seems to me, they would have the best and most accurate answer for WHY they did what they did. Don't you think?
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.