This has been the undoing of both regulators/supervisors and financial firms/banks alike. In the way of example, in the USA, the traditionally very healthy AAA rated mono-line bond insurers MBIA and Ambac changed their business model from insuring only their staple municipal bonds to insuring CDOs and ABS.
It can be argued that their contribution to making informed decisions is limited, as they tend to become unreliable precisely when, following signs of structural discontinuity, the benefits of correct forecasting are greatest. Indeed, anomalous observations that do not fit the main mechanisms at work in the historical period used for statistical estimates are frequently put aside (“dummied-out”), their information content is neutralized.