Charlene Li, founder and CEO of Altimeter Group fights the good fight in a recent Harvard Business Review article — "Why No One Uses the Corporate Social Network" — but ultimately makes a conclusion that’s not supported by her own data.
In a 2014 study, Altimeter found that deployed "social collaboration" tools aren’t widely used. (These are often called enterprise social networks, or what I’d rather refer to generically as work media, after social media). The value of any social tool increases in an exponential fashion relative to the number of users. So when few people use a tool, its value is low, and the payoff for joining is low, as well.