Valmont, stilton
What I quoted is exactly from the same issue of Safety first page 15. I don't know how did you miss what is written in bold letters. There is a difference between occasional speed excursion caused by environmental factors beyond control and deliberately doing it for a sustained period of time. The manufacturer has given you VMO/MMO. They don't have to tell you anything more. If they had your confidence wouldn't they increase the VMO/MMO figures? Commercial aircrafts are not combat aircrafts. Built like tanks is a very non professional lay man like statement. Nobody builds them even a bit more stronger than required because it adds to weight which reduces payload and increase fuel consumption.
Big difference between inflight air loads and overloads that an aircraft structure is optimized and designed for vs actual impact to the airframe in an off runway excursion.
Yah, But Sully's airbus didn't brake up despite him dropping speed considerably but 737NG broke up in Bali. You are advised to see the documentary made by Al Jazeera on Boeing especially 737NG.