Estimation is the best we have

This argument seems common to many debates: Proposal P arrogantly assumes that it is possible to measure X, when really X is hard to measure and perhaps even changes depending on other factors. Therefore we shouldn’t do P This could make sense if X wasn’t especially integral to the goal. For instance if the proposal were to measure short distances by triangulation with nearby objects, a reasonable criticism would be that the angles are hard to measure, relative to measuring the distance directly. But this argument is commonly used in situations where optimizing X is the whole point of the activity, or a large part of it.