Why car not designed to crumple for side collision and rollovers?

for the case of the side of the car: if the side doors are crumple then the people in the car would be crash because there is not much space for the crumble zone to absord the force and redistribute. also, if the roof of the car is crumple, then when the car collapses , people in the car will be crash. we want the collision force to be far away from the passengers , and the way that the crumble zone work is when the car hit something, the crumble zone reduces the initial force of the crash, and they redistribute the force before it reaches the vehicle's occupants.

hope this kind like give you the idea,