"Why are America’s adolescent boys so angry, and why are they expressing their anger through mindless acts of violence?" [update 2]

Source: Statista

"The [latest] tragic school shooting ... forces us to ask once again: What is going on in [American] schools? ...
    "The shootings have one thing in common: they all took place at school. The boys didn’t kill on the weekend, they didn’t kill after school, and they didn’t shoot up the local Dairy Queen.
     "So what’s happening? Why are America’s adolescent boys so angry, and why are they expressing their anger through mindless acts of violence?
    "That they all killed at school is a fact worth pondering. The explanation for all these shootings might very well be found in the destruction of the minds and souls of America’s young people by an education establishment bent on using our children as guinea pigs for their bizarre experiments in schooling. The fact of the matter is that most of our public schools today are intellectual and moral wastelands....
    "The crisis in our schools is at heart a philosophical issue. The precipitous rise in school violence over the course of the last decade runs directly parallel with the rise of 'Progressive' theories of education....
    "Dissuaded from making moral distinctions, fed a daily diet of an 'I’m okay, you’re okay' philosophy, denied logic, knowledge, and truth, and driven by unknown fears and anxieties, today’s young people are left with nothing but their untutored 'feelings' and 'emotions' as their guides through the trials and tribulations of adolescence. Thus we should not be surprised when they respond with outbursts of rage and acts of violence when things don’t go their way.
    "The education establishment has responded to this crisis by turning our schools into something more akin to prisons than places of learning.... A good many schools in this country are simply providing day-care for teenagers and in the worst schools, they are providing incarceration. Class time is more like a prison lockup.
    "If Americans want to stop school-yard violence and address the social pathologies that increasingly afflict our young, if they want to turn our schools into serious places of learning, they should abandon their deadly experiment in Progressive education and restore a curriculum that emphasises reason over emotions, knowledge over feelings, moral judgment over moral agnosticism, and self-control over self-expression."

~ author C. Bradley Thompson, from his 2001 op-ed 'Why [American] Schools are Becoming Killing Fields'

UPDATE 1: Thompson has updated his own earlier op-ed with new thinking and fresh writing, posting, at his blog, a new piece Our Killing Schools, Part 1. A slice:

"Your typical teenage thug is not on his school’s honor roll, does not sob uncontrollably immediately after committing an act of violence, nor does he commit suicide. What most Americans first saw in the scared faces of these adolescent killers was not so much an evil monster but rather the 'boy next door.'
    "Understandably, then, we secretly worry that these boys are not freakish aberrations but bellwethers. We worry that many more are just waiting in the wings ready for that last tumbler to fall into place activating their fateful plunge into the abyss.
    "My interest in this subject was initially inspired by my experiences as a college professor. Every year I meet hundreds of recently graduated high school students, and I am most often struck by four things: first, that students are poorly educated; second, that they hated their high school experience; third, that they are unwilling to make moral judgments; and finally, that they have inflated opinions of their level of knowledge and they are not open to criticism.The result is an often-explosive mixture of ignorance, resentment, nihilism, and narcissism. Thus, the crisis of our schools is a philosophical issue, and to understand that crisis we must know what Progressive education is and the ways in which it has affected America’s children....
    "In the next essay in this three-part series, I will examine how Progressive education has corrupted the cognitive, moral, and psychological attributes and abilities of America’s children."

(About the author: Bradley Thompson is a Professor of Political Science at Clemson University, where he teaches political philosophy. He is also the Executive Director of the Clemson Institute for the Study Capitalism and the founder of the Lyceum Scholars Program. 

    During his academic career, he has also been the Garwood Family Professor in the James Madison Program at Princeton University, a John Adams Fellow at the Institute of United States Studies (University of London), and a fellow of the Program in Constitutional Studies at Harvard University.)

UPDATE 2: Philosopher Stephen Hicks considers three hypotheses to answer the two questions that are possibly even more important than simple questions about guns and "gun control": 

• Why are young males doing this? 
• And why schools in particular? 

These killers are not targeting people at the mall or a music concert or others places where lots of potential targets are concentrated. So: What is special to the killers about schools?

Let’s start with a statistic: “Over the course of the last 25 years, sixteen teenage boys have committed a mass murder at an American elementary or high school.”* Additionally, many other teenage males were planning to kill but were discovered and prevented. So: Why so many (a) young (b) men desiring to (c) kill in (d) schools? ...

First hypothesis considers the motivation -- rule out the obvious, and you're left with hatred.

Think of spousal killing and the statistic that most domestic murders are one spouse killing the other. The relationship is close — hours and hours, days and days together constantly — but it has becomes toxic: they come to dislike and then to despise and then to hate each other. Then one kills the other.

School is a toxic place for many students. Being there is slow poison over hours and days and weeks and months — and they come to hate the place and the individuals in it. As in the toxic marriage, they want to kill the other.

So Hypothesis 1: Unlike shopping malls and concert halls, schools are toxic places for these students, and the same dislike/despise/hate dynamic of toxic marriages is operative in them. [Emphasis mine.]

Second hypothesis considers that it's not specific people the young men are killing -- it's more that the school itself is a symbol of something.

Yet there is an impersonal element in the school shootings, unlike the toxic marriages, so it’s more complicated. The murdered students and teachers very often have no personal connection to the shooter....  

So Hypothesis 2: To school shooters, School stands in his mind as a hated symbol in the same way Jew stands in the mind of an anti-Semite or Banker stands in the mind of an anti-capitalist or Politician stands in the mind of an anarchist, and the destruction of the individuals involved is generic and impersonal.

Third hypothesis considers the fact that few of these shooters expect to emerge alive. What does that tell us? And it's not just that they want to destroy themselves, it's like they want to bring down the whole temple with them:

So there’s a powerful self-destructive phenomenon at work too, something nihilistic. Yet rather than simply subsiding into insignificant lives or quietly committing suicide, they plan and execute a negative act they know will get much attention. They want to destroy themselves, and they want to cause as much destruction to others as they can when doing so.  

So Hypothesis 3: The school shooters are near-but not-quite total nihilists who feel empty except for despair and hate and a need for their lives to have at least one act of significance to define it.

Tragic. But I think Professors Hicks and Thompson are close to the answers here.