I agree this is critical for assessing the quality of a specific assessment.

But thats not the same as assessing the quality of a valuation coefficient. 

Many coefficients are developed in the abstract. ie. without a clear objective or decision in mind.

The objective is simply to understand the change in peoples wellbeing associated with a marginal change in the quality or extent of the capital. Then the understanding of that relationship is applied to different contexts with their own specific objective.

Your example of the SCC is a good case and point.