Eugenics, motive, and judgment

To put it mildly, Lombardo spends a lot of time in this book revealing the lack of scruples that often came with eugenics. The characters of Laughlin, DeJarnette, Estabrook, Priddy, and others involved in the Buck case are drawn with clarity, and the picture is not a sympathetic one. While Lombardo does reveal some motivations, most are not honorable. Priddy's motive is perhaps the most troubling since it is not really addressed. So my first question is: what were the motives of these eugenicists? Money, fame, and sex are named among the motives, as are bigotry and prejudice. Yet in the Epilogue, L. cautions the reader not to issue too stern a judgment. While it is no secret that practices continue that will be condemned in decades to come, I am not sure of why we shouldn't judge. In order to avoid repeating such atrocities, we need to continue to question the motives of key players in the game of progress today. The study of bioethics is designed to keep such questions in play. I was impressed with Lombardo's consistent consideration/treatment of ethics and wonder: should we discount the importance of the role of ethics in the writing of history? Thoughts on ethics in historiography/motives/judgments?