It seems to be pretty obvious, construction and destruction are the two sides of the same coin.
In order to effectively destroy something it helps if you have knowledge of how things are constructed.
I mean if they were really smart, they'd have crashed one plane into one tower at just the right place to have it collapse on the other tower. They'd would have also saved one planeful of passengers' lives.
Plus you don't become a terrorist to destroy things just because you know how to destroy things. They obviously did it out of radical idealism and desperation, and something else lead to that other than the fact that they knew how to destroy things.
The guys that pulled 9/11 off got lucky in many respects, on the other hand if the situation would have been a little bit different there might have been many more people dead.
These guys weren't hired guns. They killed themselves.
Then at some point in their life they found themselves in a larger pool of people that were frustrated somehow, and because of their skills they got recruited in to those particular roles.
What made engineers more in that pool of frustrated people? They could come to the US and recruit all the engineers they want. They wouldn't be very successful, and even if they do get an engineer, it wouldn't be because he/she is an engineer.
Why the pool of engineers were frustrated is a likely cause, but because they know how to destroy things doesn't make them more likely to join radicalism.
Suicide attacks are mostly limited to religious people, I think that somehow traces back to the philosophical part of religion that sees your earthly body as just a temporary vessel for your eternal soul (for want of a better word).
Almost every religion has some component to that effect.
What surprises me is that I would think that most engineers know enough about how the world really works that they would be able to pierce the veil of religion with enough doubt that they would err on the side of caution in case this body is all they've got.
When you're prepared to die it is relatively easy to take a lot of innocent people with you in to the grave.
Engineers, especially mechanical engineers, don't have to understand why the world works to be good at their practice. I mean as long as you stay away from the theoretical and stick to only the practical, your religious beliefs can always be shaped to fit around your understanding of the world.
That being said, even incredibly intelligent people believe in God. Christopher Langan claims you can prove the existence of God with mathematics: http://en.wikipedia.org/wiki/Christopher_Langan#Ideas.2C_aff...