I have a degree in history and I understand that many historians apply their ideology when interpretating history. However, this is a form of bias and is a historiographical weakness, not a strength; and in order to accurately assess any written history, historiography must be taken into account. There is only one true account of any event in history, and the best history books are the most objective history books (i.e. the ones with the least ideological bias). That being said, some aspects of historical events cannot be known - like people's motives for doing things (especially in the absence of stated motives). In these cases, it becomes a psychological analysis, not a historical analysis, per se.
So, I reject this book for the same reason I reject Marx. I believe this is a twisting of history, that seems to elevate a less prominent cause of the civil war (economics) to a more prominent role than it deserves.
I'm interested in truth, I am not excited by subjective twists.