It does seem a crazy way to design something I agree and you could design the wall to take the impact instead but......
I got called to inspect damage to the NCP in Cadogan Square some years ago which was circular on plan. Sadly an older gentleman, who had parked in one of the inner spaces, got his foot stuck under the brake pedal and jammed the accelerator down in his BMW 5 series auto. Took the handbrake off ,shot across the road and smashed into the external pre cast concrete wall. Totalled the front of the car, damaged the wall but the main concern was potential damge to the connections between panels and supporting structure. Major intrusive investigations ensued which took ages and caused major loss of revenue as bays were closed off. Cost of remedials were high too.
Armco is by far the cheaper option. Engineers eh?