The rational actor school says it's because we're all rational actors and the alternative outcome was clearly preferable.

There are other, and frequently far more convincing, models, which suggest that humans frequently make poor decisions out of near-term exigencies, coercion, underappreciated risk (pretty much just what we're talking about here), or any number of other reasons.

See: Fallacy of composition, Logic of Collective Action, Tragedy of the Commons, Prisoners' Dilemma, Red Queen's Race, Complexity Trap, among others.