The concept's not nonsense - their interpretation is.

My response to that is usually along the lines of;

1) Microsoft has already written this. Why are you repeating their work - they've spent 10's of millions if not hundreds on sorting this, why are you spending resources on trying to write functionality that's there. So, don't repeat work that's already done.

2) Where in the Agile Manifesto does it suggest data quality and accuracy don't matter - I missed thaht bit

3) For anything else that we add later you're going to have to re-implement this, meaning you're going to have to repeat yourself, and increase technical debt. Unless you've ignored YAGNI, of course.

plus if applicable. "Remember system X?"