I'm confident you can agree that terrorism and 9-11 is pretty serious as well.

People get "frustrated" when they don't get their way or they get cut off in traffic. With terrorism, people might get scared or defend themselves. With a 9-11, people might even attempt a herculean effort to keep it from happening again.

I find it strange that a serious response to a serious situation is less understandable then responding in a serious way to a frustrating one.

I can't understand anyone wanting to waterboard someone because they're frustrated or to prove a point.