It is obvious that the author was convenced by Stafford (Scientist of Empire) who is among those who think we should judge the those of the past by modern standards of attitude and behavior. Others disagree:
“Comprehending historical narratives requires, also, that students develop historical perspectives, the ability to describe the past on its own terms, through the eyes and experiences of those who were there. By studying the literature, diaries, letters, debates, arts, and artifacts of past peoples, students should learn to avoid “present-mindedness” by not judging the past solely in terms of the norms and values of today but taking into account the historical context in which the events unfolded.” (http://nchs.ucla.edu/standards/thinking5-12-2.html)