This was a big shakeup.Investors in Starbucks (SBUX 0.53%) and Chipotle (CMG -2.78%) were met with a bit of a shock recently when it was announced that Chipotle CEO Brian Niccol would be leaving the company and taking the reins at Starbucks after its CEO, Laxman Narasimhan, was ousted. Niccol was highly successful at Chipotle, while Narasimhan was not so lucky in his tenure overseeing Starbucks.The market's reaction to the news could not be more different for the two companies' share prices. Starbucks' stoc ...