We would dismiss such questions out of hand. Why, then, do we not similarly regard "What did America do to arouse Islamist mass-murdering hatred leading to 9/11?"
The answer is Leftist ideology.
I suspect that Klitzman is a morally better man than his thesis suggests. But at some point, perhaps in college, he assimilated the leftist worldview with the dogmatic but meaningless phrases that appeared in his column: "underlying forces of greed and hate," "American imperialism," "corporate avarice" and "abuses of our power abroad."
Most people who hold left-wing views when they are young abandon those views as they get older and wiser. But for those who never abandon leftism, the dogma is so powerful, it functions as a fundamentalist -- secular -- religion. Just as the Orthodox Jew, the evangelical Christian and the traditionalist Catholic views the world through his respective religion's eyes, so the leftist views the world and everything in it through leftist eyes.
That is how a man whose profession is dedicated to the elimination of psychological pain through the study of the infinitely complex human mind and psyche can have such a simplistic and morally convoluted view of America that he uses his sister's murder as an occasion to reflect on the evil -- of America.
One more example of how leftism makes decent people do indecent things.