In the piece I was watching (it was a video) the argument was being used to discuss the degreeof planning for "Agile" projects. How much is too much planning and how much is not enough? The answer lies in the experience of the team.
- Have they worked in this domain before?
- Have they worked together before?
- How much and how well?
At the inexperienced end of the spectrum the idea is almost reversed, but not quite. Yes you do need to spend more time planning, but not too much because, frankly, your inexperience means you'll make heaps of planning errors. Instead go for short milestones and correct along the way. Of course an inexperienced team does need to plan, and one of the things it should plan to do is get mentoring or coaching from someone with the appropriate knowledge and skills.
And in the middle of the experience spectrum the trap is analysis paralysis where the knowledge planning brings keeps teasing you to go just a little bit further. In this space you'd be better off starting with a clear focus on the next deliverable and reviewing the plan as you go.