My former employer was ordered by their auditors (who had permanent offices in the company's HQ building) to scrap homebrew systems that worked and adopt rhymes-with-SteepleCoughed, which did not and could not work, because the auditors' staff were trained on it.

I was peripherally involved in a failed effort to retrofit ACL onto another system, which ran on DB2 but had originally been coded on VSAM. After years of valiant resistance, they were forced to replace it with something not named Minimo, and to eat at least $60M of retraining costs, for the same reason.

Similar stories abound.