The arguments raised by Ames sound like nothing more than the age old conundrum of nature versus nurture. Impossible to determine, and more than likely some mix of both (in almost all cases of school gunmen).
And, while the criticism of the Ames treatise is valid, his social/cultural argument does indirectly raise some interesting questions (sort of twist on the idea raised by Michael Moore): Why are these sorts of rampages so much more prevalent in America than anyplace else?
Is it because teenagers in America are inherently more cruel? Perhaps, though I'd wager that high school kids in France or Japan or Canada break down into groups that are teased and those that do the teasing. Some of that is just human nature.
Or is it somehow related, if ever so indirectly, to the American ethos that tells us all we need to be the "best," or our "winner taking all" attitude to say nothing of how often kids are told that being good looking, athletic and popular are the keys to "success" (shiny things that cost lots of money!!!)?
There are no answers to any of this, of course, and there is nothing environmentla that can excuse the crimes that Cho committed. But to dismiss Ames so matter of factly is to suggest that school massacres fit neatly into a binary "either/or" explanation, which is simply not the case.
I wonder, as well, what Ames (and Weiss) would make of the Unabomber, who, like, John Brown, had a broad political mandate in mind (whatever one might have thought of his ideas) and whose actions were, at least to him, in furtherance of a greater good (and not, like Cho, designed to draw attention to himself).