I've been reading Jeffrey Kaplan's book Strategic IT Portfolio Management, as part of my research for my project portfolio book. He says something astounding (I'm paraphrasing a sentence on p.73:
Managers intuitively know when their projects are not delivering sufficient value.
Wow, that has not been my experience at all. My experience is that managers don't know sufficient details about the states of their projects to know which projects are delivering any value at all.
Managers need data. And they don't need the awful traffic lights (red/green/yellow) to tell them about the state of the project. Any non-agile project can't be anything other than yellow (if the PM is honest) until some pieces of work are finished. An agile project doesn't need traffic lights if the team creates a velocity chart and compares it to what was committed for an iteration.
It's fine to have intuition. But unless you know what to measure, your intuition doesn't have a good chance of being right. Why risk your organization's success on intuition when you can measure a few things other than dates, and greatly increase your ability to manage?