How did people come to the conclusion that "over-engineered" is something positive?
In an over engineered thing margin is left on the table which the consumer gets to take advantage of. Noting that in the real world items are often exposed to loads and demands above and beyond the idealized design constraints a 'perfectly' engineered item would just meet.
From the article itself: "Over-engineered, absolutely. [...] Every check earned its place by catching something I’d otherwise have shipped. Would I do it again? Without hesitation."