You've heard variations of that i'm sure.
A common misrepresentation is that you when you deliver using in an iterative fashion, you don't focus on the entire scope of the project and you don't commit to deliverables. This scares business people. It would scare me too. If only it were true.
It's generally accepted that even a traditional project plan built from the bottom up is likely orders of magnitude inaccurate. The cone of uncertainty depicts that quite well.
If a team can't give you a good ball-park estimate on what you'll see at the end of the project, it's probably because they know your business requirements are going to change over that timeframe.
And that's allowed.
Instead of thinking if it as a bad thing - think of it as a better way to react to the changing environment. How quickly you can react to fulfill a customer need is a success criteria every business should use.
Besides - you won't have to fill out any more change requests.
