Computer programmers had to be concise, if not elegant, in their work. And when that happens, chaos ensues. How much chaos no one really knows. But to get a feel for the size of the problem, just imagine how many credit cards will be rejected simply because the computer thinks that cards expiring in 2000 already expired in 1900. It is ironic that this great, complex society we have developed could be hobbled by something as simple as a programming shortcut.
Computers can only be as good as their programmers.
People are often under the misconception that computers can magically operate beyond the limits of human intelligence. Computers sort, calculate, simulate, and project faster and more accurately than we do, but that's about it. Deep Blue, the computer that beat Gary Kasparov in chess, wasn't more intelligent than him, rather the team of human software engineers that designed the program were, collectively, more intelligent. Anyone who has ever written a software program knows that one of the biggest challenges in the endeavor is anticipating every potential scenario. If one doesn't address every case, the program crashes.