Generally speaking, academics in the USA, including civil war historians, are liberals, that is, ideological leftists.
That means they are about control, as in "Who controls the past controls the future; who controls the present controls the past," a slogan of Ingsoc in Orwell's Nineteen Eighty Four.
They are the gatekeepers of knowledge and information about the past. They control the spigot, determining when information about the past trickles and when it gushes. They not only control the rate at which the info is released into the culture, they control what information flows through the spigot.
They are less interested in the reality of the past than they are interested in controlling the past to control -- to determine what happens in -- the future.
But their apple cart has been upset, if you will pardon the mixed metaphors. In the present, somebody is messing with their control of the past. A whole 'nother spigot -- the Internet -- has come along and given control of information about the past to whoever wishes to take it.
Thus, these days nearly anybody can control the future by controlling the past.
And the gatekeepers are UPset...