[barrkel]

Aiming for perfection wouldn't have delivered the product any sooner, of course.

Zero defects is something worth striving for at the lower levels of a product, stuff that is heavily reused by higher architectural layers. When you can have breakage at any level of the stack, engineers need to have too much context in their heads to correctly detect and resolve issues. In the worst case, they make local fixes that don't address the underlying problem, which turns into scar tissue that can make the underlying problem harder to resolve, besides damaging the codebase.