There have been some interesting books on how to survive (or not) in many kinds of emergencies; I have a documentary on that in my Netflix streaming queue. Most people do just freeze in ways that are counterproductive.

The addition of "hide" makes perfect sense to me. For instance, a number of students who survived school shootings did it that way. Similarly, advice for hostages--blend into the crowd of other hostages, don't stand out in any way--is an equivalent while you still have to be literally visible. I can see the advice causing most problems when you don't know if the problem is a human attack or a natural disaster.