Stop Drop and Roll

Because the main purpose of movies is to be melodramatic --- exude feelings and emotions.

Everybody calmly doing what they should do is not dramatic enough. They must express emotion --- dramatic emotion.

The same reason in movies when emergencies occur, everybody runs around like chickens with their heads cut off, screaming and yelling.

In real life people more often than not calmly react to emergencies in an orderly fashion. But that would not be dramatic enough for a movie. They think, "We need to feel what the characters would be feeling."

And unfortunately they think negative feelings --- fear, anger, panic, doubt --- are more dramatic than positive feelings --- confidence, rational thought, effectiveness and efficiency.