For me it felt a bit like a science book with fascinating insights. Yes, what happened in those places was awful but that wasn't the focal point of the book IMO. The focal point is an analyzed account of how people have a higher (or lower) chance of survival in such a dire setting.

Also his book are secretly 2 books for which this part is the first part. The second part is about Logotherapy, something he developed after WWII based on the insights he gained from people in concentration camps.