give the filmmakers some credit
OK, so the Bonatti material was distracting and should have been the subject of a different documentary. But the photographic reconstructions were amazing. I don't know where they shot those scenes but they certainly could have fooled me if I hadn't known they couldn't be the actual location.
As to the climbers' choices, it's true that they had waited through a long period of bad weather but it's also true that that many people - in several parties - embarking on such a perilous climb is asking for trouble. If one or two of the parties had chosen to wait till the others returned they might have got their chance later. It was still early August.
I also wonder about that bottleneck. It's an obvious death trap and had killed before. Did no one ever explore the sloping rock ledges to the left that would have let them avoid the couloir entirely? (There is one bit you can't see that might involve a single rappel but that seems preferable to spending hours below a giant sword of Damocles.)