It's a result of Nuke guilt.
Ever since we won WW II our home grown commie's (CommiecRATs & their leftest press,)
have been telling our children how terrible we were to use the Nuke.
Sadly, each generation believes that bs more than the previous one.
Seventy years of non-stop Liberalism plus worthless American/Western History education in the even more worthless (but prohibitively expensive) public schools and endless leftist hotbeds known as "Universities"!
In my opinion, I really do not have a definitive answer to that question. However, as you mentioned, it's a different generation. I do not want to criticize the "good" Baby-boomers, but this country since the 1960s has really gone down the toilet (except for technology and Civil Rights for blacks). The baby-boomers that went to college thought they were smarter than anybody else, because they went to college. However, as a recent graduate myself, I know college does not make a person smarter. Once these boomers got into power (politics, business, education, etc.), American society began to drift from its roots. I don't want to disparage millions of people, but hey, I had baby-boomers who raised me. They act odd.
Why are things different? I'm not sure, but I think the stench of liberalism has permeated the media and the educational system. We have a population that's being brainwashed to hate America to go along with a "blame-America-first thinking." NY Times, Tribune Co. papers, television networks, etc. Most people here are intelligent, but most of the American people are ignorant regarding political affairs. They are easily lied to by the press, and that has a tremendous affect on the population.