Or are you saying you base your level of happiness on the experience level of the coders involved rather than their test coverage stats? Because last I checked, experience levels meant very little. The Tacoma Narrows bridge was designed by - at the time - the foremost structural engineers in the world. Their paper on its design was recognised as the single most important paper of its kind in that decade. The bridge still fell, not because they were wrong, but because of something nobody had encountered yet (in this case, aerodynamic flutter).
Critical code is precisely that - critical. You don't leave it to the "gifted engineer" model of development because that always fails. Noone is gifted and diligent 100% of the time, everyone screws up eventually. It's dangerously arrogant to think otherwise. You build a system of work that lowers the probability that those screwups make it into a working system, that's all. Civil and Mech. and other engineering branches have been doing it for decades. We're just getting started on it in this branch of engineering.