No one disputes that those events you cite happened. However, those events were essentially random, not caused by local efforts to stimulate industry. Because of them, the area was blessed/cursed with an excess of productivity that it didn't know how to cause.
Now it's just coasting downhill, unable to maintain the altitude that it once had because it never knew how to (was never possible to?) build that altitude without a big dose of random luck.
Now it's just coasting downhill, unable to maintain the altitude that it once had because it never knew how to (was never possible to?) build that altitude without a big dose of random luck.