Hi,
It is my belief that Boeing aircraft are more heavily constructed than the certification requirements dictate ...
It is also within the boundaries of good manufacturing practice that when a hull is exposed to excessive "G" (crash) that there is a regularity to the fractures ... that would be considered at the design stage, similar to the expected deformity of a car after impact.
As commented before I find your comment interesting and after reread .. more interesting than at the first reading.
Indeed if
"that would be considered at the design stage, similar to the expected deformity of a car after impact."
The logic is :
One can ask why put in first place passengers in a aera knowed as a "fracture aera" and so a very dangerous place (lethal in many cases) to be in case of "road excursion"
Are the people in a car seated in the deformation aeras ?