Alienation and hatred
What a pile of steaming lemon-pepper malarkey. "Alienation" is not the same thing as fanatical hatred. The Boston bombers weren't disaffected youth; the problem is that somebody affected them.
These brothers were not "rebels without a cause." They had a cause. How many times does the surviving terrorist have to repeat that before it penetrates the thicker skulls?
They weren't "misunderstood by the world." The Tsarnaevs are the ones who had a deadly misunderstanding.
Adolescents almost always pass through a stage where they feel disaffected, and find it tough to fit in. That can be shaped into healthy impulses toward independence and achievement with the guidance of father figures; we admire men and women who make their own place in the world. These cretins, particularly Tamerlan, declared war on the world around them. Thanks to the welfare state and academic culture, they had time and money to prosecute that war.
And in any event, they weren't "adolescents" at all. They were 26 and 19 years old. Whose idea was it to create a society in which 26-year-olds are still regarded as children?