I think we all agree on that; the problem is that some customer relationship management is .. highly political. Lots of face saving and message discipline. Engineers are not trusted to have the skills to do that even if you've got time to keep them fully briefed on what the story you're allowed to tell the customer is.
Sometimes even asking the wrong question can cause an upset. Engineers are prone to thinking or even saying things like, "successfully delivering the project is more important than the ego of a middle ranking procurement manager in the client, right?"