Should the Director of the CIA have resigned?

Based on just a few reports on David Petraeus, it seems as the he was dignified and well respected for his work in the military. Seeing as how he was also a general, that shows he had great talent for being a leader. For having 37 years of service in military affairs, even Obama said in a statement that Petraeus had provided "extraordinary service to the United States for decades" and had given a lifetime of service that "made our country safer and stronger." If Petraeus feels that he isn't fit to lead, then that's his decision, and everyone should respect him for being honest about it, especially since he was only director for a year. If he was so distinguished and professional though, I think he should have stayed in command since we need more men with his skills.