Your question reminded me of the following quote:
It Is Difficult to Get a Man to Understand Something When His Salary Depends Upon His Not Understanding It
Maybe here we are talking about an alternative version of this:
It Is Difficult to Get a Man to Say Something When His Salary (or Relevance, Power, Influence, Status) Depends Upon Him Not Saying It
Your question reminded me of the following quote:
Maybe here we are talking about an alternative version of this: