ChuckMcM was using jargon that is used especially in markets that are closely tied to academia (pharma, etc.) in which the thought leaders are the influential ones. Extending his 'metaphor' to other groups, thought leaders then would be the members of any group that influences how people think. Thus(sadly) it is true that athletes or other celebrities who may not be qualified or expert in a domain can be, ipso facto, thought leaders to a significant group.