A title people give to above average CEOs to give attention to the fact that they and their company exist, usually in an attempt to increase their social value.
ex1: I just met Nancy, a rockstar CEO, whose company is building solar powered televisions priced at 10,000$ for people in developing countries. ex2: I've never heard Mark Zuckerberg, Bill Gates, or Evan Spiegel referred to as Rockstar CEOs. You know why? Because nobody has to say something so corny to shed light on the fact that they are incredibly good at what they do.