It's worth noting that 'merit' in the 'test scores' approach just means scored X on test Y and/or Z on test W. So if (for example) someone gets low SAT scores, but cures cancer, they don't get admitted, because 'cures cancer' isn't part of the admissions criteria.
Setting aside the fact that in reality the person who cures cancer will get admitted because colleges take into account academic honors and achievements, and setting aside the fact that there is a high correlation between test score and likelihood of discovering a cure for cancer, the point you are making is one of "what constitutes merit," which is entirely tangential to my original point (which in no way equated merit to solely test scores).
