Benefits and shortcomings of a project do not accrue until possibly years later, well after the project's originators have passed from the scene. When the shortcomings do become apparent, the incumbent policy makers can justifiably place the blame upon their predecessors.
Following severe criticism of the civil service in the UK in 1993, in which government ministers had shifted responsibility onto civil servants for withholding information and misleading Parliament, a code of ethics was proposed by the latter to avoid such accusations.