One of the things with a modern monocoque energy absorbing design is that they are intended to "look pretty much intact", but there are hidden parts of the structure which deform in addition to the visible damage. Once those areas have deformed, the structural integrity is gone unless you find every single one and replace them perfectly to their "as new" state. It's not necessarily even as simple as cutting off the ends and welding new ones on, as there could be small amounts of structural damage along the entire length of the vehicle. Another feature of monocoque design is that anything which has twisted (rather than crushed) in the process of absorbing the energy can't just be straightened, as doing so leaves you with a structure that is still weaker than designed. Monocoque designs are excellent for achieving maximum strength for the weight, but any serious deformations, twisting, over-stressing, etc compromises the strength of the entire vehicle, and very easily becomes so costly to repair that it's just more economic to scrap and build new.
It's a trade off between excellent crash survivability, repairability, weight, and cost. The demonstrated survivability is excellent design, and the inability to repair tells you very little about the quality of the design. If you wanted a design offering that level of crash survivability as well as repairability, it would very likely need to be much heavier and more expensive. The safety benefits combined with the infrequency of major damage makes it a reasonable design choice.