History professors have been very willing to overlook the overt racism of Woodrow Wilson, perhaps believing that his League of Nation ideals superseded bigotry. Historians overlook the racism of Theodore Roosevelt that led to the murder of many Filipinos. Bigotry was superseded apparently by Teddy's bold character and domestic policies. I don't think that it's appropriate to bash Truman for the words. Leaders should be judged by their works and words spoken in public.
People can grow and change.
I have two sons in their twenties. One is in college, the other is in the Peace Corps. I will have absolutely no objection if my sons enter the military. I did so. Fortunately, I did not have to do Vietnam.