Imagine if construction/aviation/etc engineers wanted their building/bridge/airplane to be whimsical and have its own personality. Are you scared yet?
Imagine if your out-of-band(not in the initial requirements/spec) and whimsical software contribution was responsible for a bug that brought down an airplane, or killed a patient. How whimsical would you be then? Well at least you wouldn't feel bored at your day job right? Anyway, I think you get my point.