Intel – one of the all-time great American companies – this week had to suffer the indignity of a public letter from an activist hedge fund investor, urging it to break itself up.  Dan Loeb is the Principal of Third Point Capital. He’s been building a stake in Intel for a while. This week he published a letter castigating Intel for production delays, and urging it to consider spinning off its microchip production business. “Once the gold standard for innovative microprocessor manufacturing, Intel has lost its pole position to TSMC in Taiwan and Samsung in South Korea”, said Loeb. “We…