Income tax law. The system of tax codes is so complex, and the stakes are so high in every change to the code, that corporations always end up putting accountants in charge of the company. Why? Because statistically, only accountants can prove to boards how much more they saved the company on paper by manipulating their adherence to complex tax codes (and benefit cuts). Even in companies that still have a practicing engineer in charge, that engineer will be outnumbered by the herd of accountants that are needed to adhere to tax law (if they bother to even do so rather than just lobby for special dispensation: a highly profitable venture these days).
We can explain “slow is fast” all year long, but on April 15th, all of our practical usefulness words are lost in the hurricane of spreadsheets and dreams of write-offs and short-term projections of the budget butchering spreadsheet sword.