^ I agree. I look at it as a bit of a two-tier process:
- The grades (and curricular rigor) and test scores need to meet the threshold to assure adcoms that the applicant will be able to handle the level of courses. If an applicant doesn't meet this threshold, it's a very tough sell. But it's also pretty much impossible to separate applicants based on these factors alone, especially given school and curriculum heterogeneity, grade inflation, tutoring, test prep, superscoring, etc.
- ECs, essays and LORs provide a much greater basis for separating out applicants. But they won't make up for major deficiencies in grades and scores.