Upvote:3
I am recasting the question as follows: "Among the people who helped make the decision to drop the atomic bomb, were they mostly privileged Ivy Leaguers or were they all Trumanesque "school of hard knocks" graduates?"
Truman formed the so-called "Interim Committee" in May, 1945 to help him make this decision. I find it interesting that the two southerners, James F. Byrnes and Paul Clayton appear to be "school of hard knocks" graduates, while the northern-born men were all privileged Ivy Leaguers. The latter included former Secretary of War, Henry L. Stimson, Ralph A. Bard, Undersecretary of the Navy, Dr. Vannever Bush who headed the Manhattan Project, Karl Compton., James Conant, and George Harrison.
I can't identify any historians that have done the kind of biographical research outlined above, or made the observation cited in the original question, but I wouldn't be at all surprised to find that someone had done one or both.