You intimate that there is a "generalizability" concern about descriptive studies which limits their publication in general interest journals, but that does not explain why RCTs do get in as the generalizability problems are just as severe. But, just one example the general interest journal AEJ:Applied Economics published a paper in which the "treatment" was establishing "village based" schools in 13 (!?) villages in one province (Ghor) of one country (Afghanistan). And that finding is worthy of publication in a top economics journal because....of its generalizability? How so?