I like that comment about crash axe vs. two quarters and a dime and a set of car keys.

However, this one I disagree slightly: "Could this crash have been prevented if a flight attendant had been in the cockpit? “No,” is the short answer. "

The presence of a flight attendant does not make it impossible for a determined suicidal co-pilot to crash the plane. Heck, even the presence of captain doesn't. But while you can physically destroy the plane even if someone is right there, in the case of a mental disorder it is more difficult to do it. The presence of another human has an impact on you.