Eight years ago next month, Facebook’s Mark Zuckerberg sat down and wrote a letter to his shareholders. In language that seemed so natural, so human, he laid out what Facebook had done for the world. “We believe we have created a greater number of stronger relationships between people, and that it helps people to get exposed to a great number of diverse perspectives.  By helping people form those connections, we hope to rewire the way people spread and consume information.” It all seemed to suit the times – an era when social media and emerging applications would bring communities and the world together.  Zuckerberg had made the commitment that Facebook would never grow into a company obsessed with revenue and profits.   None of this turned out to…