We won’t find out if Mark Zuckerberg can fix Facebook by asking him. People run companies because they love to run them, and hate to lose them. For that reason, it will be up to the users to make Zuckerberg's choices in the long run. Given Mark Zuckerberg's experience with Instagram, I'm not sure if his fast rise is going to last the way he hopes. The company is beginning to see the financial fruits of its social network, but its entire business model may not be sustainable. Investors may soon decide they have had enough.