a stage in psychosexual development when the child's interest is concentrated on the anal region; fixation at this stage is said to result in orderliness, meanness, stubbornness, compulsiveness, etc.
And here is another reason why: it has given corporate bean counters and other anal-retentive types yet one more excuse to orient their companies not towards actual real-world results, but towards precise fulfillment of the demands of government reporting.