We all well understand "ahistorical' and the need to avoid projecting the modern into past motivations, actions, and analysis. This has natural limits: in Civil War readers you either see those limits where they don't belong or no limits at all.
How many readers who are politically self-conscious Democrats, for instance, read Civil War history with a personal bloodlust for absolute war and a curdling contempt for commanders who restrict military and civilian casualties and damage to property? Isn't that kind of separation within the personal very odd?
I found the same attitude in modern military men with whom I once served - they were Lee, Grant, or Patton in their reading time but meeker than Samuel Cooper day-to-day. On a visit in Germany once, I was stopped in a brigade HQ convoy for 45 minutes during a winter deployment because neither the commandant nor any of the staff could be bothered to leave the warmth of their cabs to walk up the line of vehicles to see what the hold up was (it was a sliding truck, easily parked at the side of the road for later retrieval). These fellows drank Civil War history from the golden spoon of Centennialism and venerated all the approved saints - none of whom seemed to have anything to offer anyone in modern circumstances.
The most public disconnect is in the effort to stigmatize vs. honor the Confederate historical legacy. The legacy folks seem to have one of those Civil War walls between past and present that allows one mindset here and one there. This drives the stigmatizers crazy. They have the opposite of a wall at work, with past and present all mixed up.
The stigmatizers are adamantly committed to the paradigm that the war was about one thing only, slavery, as was the South, and that any dissent from this view is immoral or ignorant. The good part about this package is that at root is an unwillingness to disengage from the original debate AND from personal moral convictions held in the present. The bad part is that a personal moral/political position has been disguised as an historical argument and injected into history discussions by people too agitated and confused to simply say "I cannot relate to a slave state," or "I would be embarassed to claim the history of a slave state, whatever the facts of the matter about secession, be they free trade, northern tyrrany, or what have you."
There was a film about Thermopylae a few years ago. I skipped it. I can't relate to Spartans. I know too much about them. People ask me if I have read Dostoevsky. I's not going to happen. He was a monster.
Those on the other side of the stigmatizers fool themselves when they say "Those times were different and values were different." Of course they were - and we're different and we cannot honestly assume the values of a past generation whom we never met. The legacy crowd is quite correct, however, whenever it says, "We are looking for ways to relate to this," or "You cannot characterize the motivations of secessionists with a single paradigm." Our legacy friends should likewise not disguise personal interest with historical rationalizations.
People round on me when told I will never read Dostoevsky. They give me all sorts of things I am going miss and why this person must be separated from his work. Good for them; I do listen. Let the CSA legacy crowd tell us the "why and what" of honoring in terms that do not require us to settle the cause of the war or the meaning of the CSA.
p.s. You see this same dichotomy in discussions of whether Lincoln was a tyrant or not. On one side, personal moral outrage is brought to bear on the actions and circumstances of this president; on the other side an eerie, amoral disinterest is deployed to defend Lincoln on historical grounds against what is patently personal revulsion.
p.p.s. Suspect I will regret this post soonest.