Positive claims are about what is true. Normative claims are about what should be true, or rather what decisions we should make. Put another way, positive claims deal only with facts while normative claims deal also with values.
GP is saying that it's the data-scientist's job to give the executive the facts and it's the executive's job to decide what to do about the facts.
So often, those models proved to be over-fitted and not generalizable.
But too many decision makers simply can't properly judge such results.
Where do business analysts fit into this dichotomy? Their whole job is to poke around in Tableau in order to surface high-ROI strategies for the business to pursue. (Where, in choosing which proposals to surface to management, they're effectively making 90% of the strategic decisions.)
Or how about corporate buyers in trading and retail companies?
Or quantitative investment managers?
If understanding the data generating processes is the goal, I'd rather see some useful plots than wade through a technical description of some model whose assumptions were flagrantly violated.
Ouch. This is savage, but sadly correct in many cases.
HOWEVER, to play devil's advocate here, I've also seen corporate data scientists overstate the conclusions / generalizability of their analysis. I've also seen data scientists fall prey to believing that their analysis proves would should be done, rather than what is likely to happen.
The role of an executive or decision maker is to apply a normative lens to problems. The role of the data scientist / economist / whatever is to reduce the uncertainty that an action will have the desired effect.