Corporations hold tight reins over its legislators and executives, enabled by the (relatively) tight verification loop of the quarterly financial report. This is a double-edged sword in that corporate goal-setting is often either 1. short-sighted or 2. absurd moon-shots, but largely speaking this has lead to a good deal of success in the past century.

Nations have need of such mechanisms when there are no such thing. You cannot the measure the success of a nation on the figures of a balance sheet, and even if we could the consequences of executive decisions can only be reliably gauged on the time-scale of decades–thus, if we’re to believe the lofty promises of a businessman-cum-president it cannot be on the promise of his goodwill.