Tim Cook’s fifteen-year run as Apple’s CEO is closing not with a victory lap, but with a sharp reminder of the limits of his signature skill set. Apple investors responded by promptly erasing some $350 billion in market value. St.:‎The problem wasn’t the quarter Apple reported. It was the quarter ahead… Importantly, Apple isn’t warning that customers are disappearing. They exposed the limits of even Tim Cook’s supply-chain expertise during an industrywide shortage unlike anything the company has previously experienced.