Because it is intrinsically human to act on impulse when overloaded
Had a C & T who taught that to all pilots on a conversion to a new type helo, everyone fell for it. Previous type had the fire handles top centre below the instrument panel coaming, ie in full view. New type had had this caption just under the panel coaming directly in front of each pilot. Throttles, fuel shut off and fire handles were in the overhead.
Trick played was at the end of a training sortie and the engine cool down requirements had been met he would give you an engine fire, right hand caption in the block of four, #2 engine, right? Well, everyone grabbed the #2 engine fire handle which also closed the fuel shut off and closed the throttle. Problem always was the fire he simulated was in #1 engine. Lesson, cockpit ergonomics of having the fire warning caption immediately above the #2 engine out caption, AND LOOK AT THE FIRE HANDLE TO SEE WHICH ONE IS LIT.