Having been in Air Force ROTC and meeting a lot of the people who are going to be those flight crews, I can tell you none of them would look forward to shooting down a civilian airliner.
However, I know that, were they ordered to do so, they have confidence that such an order would only be given in the most extreme circumstances. The Hollywood protrayal of trigger-happy generals wanting to vaporize the Soviet Union and kill everything in sight is just that: A Hollywood stereotype.
The only "bomb-happy" general I can think of in Air Force history is Curtis LeMay, who never dropped a bomb he wasn't ordered to drop. And it is largely thanks to him that the Air Force is such a professional organization with so many fail-safes against "Accidental Weapons Release".
I'm also glad that they're training for this several times a week. Before, Air Force pilots only got to train a couple times a month, seriously reducing their overall effectiveness. If they're flying several times a week; Hell, even once a week, they're going to be that much better, and better prepared for any situation.
Those who fail to learn history are doomed to repeat it in summer school.