This issue can not be blamed on the bean counters. Do the accountants decide on the manning levels? This is a problem for management, shareholders/owners and regulators. Unfortunately there are some "latent errors" that seem to be too expensive for companies to contemplate addressing. I would suggest that in a situation where chronic fatigue of crews can be reasonably foreseen by the regulator, if no remedial action is mandated and enforced, then the regulator should be jointly culpable for any damage, injury or loss of life which results.
sr