Chris Blattman rants against the resistance to trying to estimate cost-effectiveness that he has encountered in the aid world. One thing he writes about is the “we do not experiment on people” argument (counter: there are always some who gets the stuff and some who do not).
Another expression of reluctance to measurement that I have encountered is: “We understand that we should be held accountable to donors, but why the need for such tight control? Don’t they trust us?” But this gets wrong the rationale for measuring, which primarily is to learn about the effects of what we do in order to do it better. Even if you are not accountable to anyone, measurement may help you learn what you do best and to improve.