Yes, the bullwhip effect is caused by uncertainty across coupled tasks. A plan that doesn't reduce and manage uncertainty is bad. Not having a plan means there is uncertainty
even when all of the information is there to determine the answer. The empire state building had a plan for obtaining steel from foundries at the velocity they needed.
If one defines plan to mean "We schedule everything up front and then stick our fingers in our ears and say 'la la la la' when reality conflicts with our imagined schedule" then of course plans are bad. Similarly if one were to define agile as "a system that is incapable of delivering any feature that takes more than 2-4 weeks to develop" then agile would be bad too.
