Earlier quoted context omitted.
In America lots of people have died in single stairway buildings. The Triangle Shirtwaist Factory fire created a political dynamic where buildings are expected to have dedicated fire escape stairs and that remains a strong social contract to this day. https://en.wikipedia.org/wiki/Triangle_Shirtwaist_Factory_fi...
maybe since then there is a better local optimum in this problem-solution space, hm? fire safety engineering is a very respectable field, mandating a particular implementation instead of a required safety level is the opposite to good long-term policy.
Indeed, that seems likely. But there are political and social realities to consider. If what is optimal is something along the lines of: "In case of fire, if there is a fire escape then use that, otherwise shelter in place" then a conditional that must be evaluated ends up embedded in the emergency plan. This is a much bigger problem than is immediately obvious. If everyone knows that in case of a fire one should exit through the fire escape stairs then this leads not only simplification of emergency procedures but also their enforcement. In America seeing a fire escaped blocked or chained up is cause for immediate alarm and enforcement with the general public being perfectly capable of basic inspection themselves. Having an extremely simple plan for fire safety can help increase reliability because everyone knows and understands the plan, can contribute to enforcement, and execute the plan when there is an emergency. Engineering optimization not only does generate conflicts with social and political realities but in fact almost inevitably does so.