The word ‘plan’ evokes many emotions, not all of them pleasant. The root of the problem is a nearly racial memory (I have been reading Jung again) of an intricate project schedule developed before the first requirement was ever collected. The plan even went so far as to promise a delivery date. The knee jerk reaction to what is perceived as over-planning has always been to avoid planning altogether and to trust that feedback loops will guide you to the goal.
The problem is that, without even the most rudimentary planning, when you are just reacting you are guilty of tampering. Paraphrasing a bit, tampering is defined by Dr. W. Edward Deming as changing the system based on feedback, without at least some knowledge of the path you want to take and the capacity of the system. Deming’s Funnel Experiment, where changes are made to the system based on a single outcome observation, proves that tampering with a system without a bigger picture will cause greater variance than if you do nothing at all. And we know how well that works. Having enough of a plan, for example a release plan in Agile, can provide the context needed to reduce variability, or at least saving the variability for the real surprises.
Our goal in any project is to deliver value as fast and as well as possible. The right kind of plan and feedback will help stop you from wandering aimlessly.