The article talks about measurement of impact as though it's a totally value-neutral idea, but it's absolutely not:

  * Measurement requires substantial logistical overhead; both up-front in creating a plan for measurement, and during intervention due to the extra record keeping involved. This is a (probably frequently large) drain on program efficacy. Just listen to any schoolteacher's take on standardized testing, evaluation rubrics, etc.
  * Some contexts, and some types of intervention are more amenable to measurement than others. Insisting that nothing which is not measured can be valuable biases our decision-making towards the most measurable actions, which are likely not the best. Strong correlation with simplistic actions, short timelines, and lack of responsiveness to individual context.
  * Goodhart's law.

Author (and everyone) would benefit from the book Seeing Like a State.