I wasn't thinking of this basket so much for rooftop evacuation but possibly 'dangling' the device alongside the building (as least as far as the line length would permit).
Perhaps some (even if it were just a few) could have been saved this way?
One of the many things 9/11 demonstrated is that in a 'new' war there are going to be different rescue and recovery requirements. In WWII there were no high rises to contend with but I would say that in any future conlict where urban centres are targeted, high rises would represent a risk in terms of rapid evacuation.
Some buildings have 'escape ropes' installed near their windows which allow occupants to absail out of the building but .. lack of training in their deployment, height restrictions and a general apprehension towards their use means they are likely to be of limited effect.