Nobody decided to destroy the business. They decided to defer the problem. Each individual deferral appeared manageable — a technical debt left unpaid, a compliance gap papered over, a number smoothed to hit a target, a safety concern noted and shelved. The organisation accumulated these decisions the way a building accumulates structural damage: invisibly, until the load becomes fatal.
DZ4 is distinguished from individual bad actors by its systemic nature. This is not one person making one catastrophic choice. This is a culture of quiet accommodation that spans teams, tenures, and time. Insiders knew. The knowledge was widely distributed. The capacity to act on it was structurally suppressed — by incentives, by hierarchy, by the collective understanding that naming the problem would cost more than deferring it. Until it didn't.
The human signal here is specific: the engineers who knew, the managers who suspected, the auditors who looked away. DZ4 is the failure of collective moral courage at scale. The rot was rarely hidden. It was tolerated.