That sounds like "denial". People in emergencies often have an almost wilful inability to understand how bad things are. For them, the situation is unprecedented; even if it has happened before, it hasn't happened to them. Big disasters are so rare they are not the first explanation you should reach for. People also tend to freeze rather than panic, which may be related: if you don't know what's going to happen, any action you take may make things worse. Since you are still alive, where you are now is relatively safe, so why move?

9/11 was pretty much unprecedented anywhere. They did not expect the towers to collapse just because they'd been hit by a 'plane. People in the second tower had no reason to expect a second aeroplane. Evacuations are dangerous; people get injured during them.

It's still not clear to me what happened there; what exactly the captain and crew knew when. However, I gather the ship is made of compartments, and being holed in one or two of them does not mean it will sink. If the ship isn't sinking, then it is probably the safest place for the passengers (because evacuation is dangerous), even with water pouring in over the generators and power lost. As it happened, three compartments were holed and the ship did sink, but that may not have been apparent to the captain until later.

I'm not sure how that's relevant. How were "a few" sacrificed in the given situations.

Generally I prefer REDACTED to conspiracy. I don't think the people giving advice to return to desks/cabins were trying to sacrifice anyone. They were giving the best advice they could. It happened to be wrong.

That, for me, is the take-away. The people in authority may be ill-informed or suffering from denial or other cognitive disorders. They may be following a play-book that is not appropriate to this exact situation.