"When building a complex system, having crackerjack programmers (who can make any design work, even a bad one) can be a liability. The result, after lots of effort, is a working system that cannot be easily maintained or upgraded. Good -but not great- programmers would fail early, causing a realization that the system must be redesigned, and then reimplemented. The extra cost is paid once, early in the system's cycle (when it is cheap), instead of repeatedly paid late in the system's cycle (when it is more expensive)."