Brian Niccol took the helm nearly a year ago, but results have been disappointing.It's been one year since Brian Niccol took the top job at Starbucks (SBUX -0.47%). The move surprised industry observers. Niccol had earned a reputation as a turnaround specialist after getting Chipotle rolling again when the burrito chain was still reeling from the fallout of an E. coli-related crisis that started back in late 2015.Starbucks stock jumped roughly 25% in a single session on news of the burrito whisperer's arriv ...