Washoe, emergency planning for a nuclear attack on the US will never involve planning to fly US citizens out from the country one by one by helicopter. Do you understand why?
I mean, after the fact you can ask 'why not' but it is just not something they will plan for.
And btw no person stuck at floor 100 would be able to get on to a helicopter hovering outside the window. There is simply no way to just throw them a rope and have them traverse that distance. They would have to jump down and once the rope became taut pulled up or the helicopter would have to take off fast in the opposite direction and just yank them out of the building. There is a reason all helicopter rescues tend to have the professional first lowered to the 'victim' who is then secured and the professional then brings them out.
The danger of a helicopter doing multiple close proximity trips to the side of the building and risking blade contact with the building would also be immense. Towers like that cause massive swirling and unpredictable winds, put aside the added risk of explosions caused by the fire inside. One falling helicopter that crashed into front lines workers below could easily cause far more casualties than all helicopters in service would save, one by one.
But as I stated in the other thread, 9/11 did make me take one precaution that was easily within my control. I did a lot of Rock climbing when younger and know how to repel. And as my office was on a high floor (52nd) and I always pick condo's to live in on high floors (currently on 32nd), I bought and keep 2 sets of ropes (200ft each) and my repel harness and gear.
Make no mistake, as I think the odds of ever being in that situation are miniscule and moreso being one in an area to survive it are also miniscule.
But should I find myself in that horrid position, whether via natural disaster (earth quake, terrorism, etc) where the building was compromised, stairs and elevator inaccessible and the fire or other death inside the building was coming for me, I could at least try to find a window to break on a side of the building where I could repel down, 200ft at a time before resetting and traversing the next 200 ft, in the hopes of reaching the ground, or an area of the building where i could access stairs to get to the ground.
I imagine seeing me scaling down the building like this...
...would make for a lot of news fodder for a long period thereafter.
The WTC would take about 7 resets of the ropes to hit the ground whereas my current condo would only take 2.