as the French learned to their cost

Query: since the French learned the value of this weapon, why did they not in subsequent generations adopt the use of the longbow?

The French could have easily understood and duplicated it; the technology was readily available. How extraodinary that a people, vanquished by a superior weapon but having the technological sophistication to produce it for itself, did not do so. Why, historically, did they not?

And can anyone present historical cases of like inaction? I am aware of only one.