Earlier quoted context omitted.
Is this basically subsidizing a slightly higher survival rate for a relatively few number of fires with a significant loss of space for everyone?
Im not sure if I am reading your comment right, but if you're offering a choice of less space or higher survival... I mean, think of all the wasted space and weight having 8 exit doors on a airplane; they don't crash often
And if we had all doors except one passenger seat, it might be even safer.
We neither optimize for absolute highest survival rate nor for absolute highest convenience/efficiency.
The question is-- how much does the second staircase improve survival? Is it the most economic way to get that survival difference?