There are parts of some jobs where perfection is required. People working at height don't drop anything (and there are cases where safety lines aren't possible). Surgeons don't get to just say "oops, my finger slipped" when holding a scalpel near your heart.
In "From the Earth to the Moon" [1], someone explains that the main problem of the Apollo 1 fire was that nobody thought to label that test "hazardous". Sitting on the ground was supposed to be safe.
We should expect perfection when writing C code, but we should also be clear that writing C is a hazardous activity, and not to be taken lightly. My surgeon is a human being, so I don't expect him to never make a mistake, but he's also a skilled and careful professional, and I do expect him to never make a 101-level mistake while holding a scalpel.