[AStellersSeaCow]

>What's frustrating to me is that there's this sort of all-or-nothing attitude about testing, where tests are seen as useless, or as a perfect indicator of skill or ability. The truth is in-between.

Yes. This is a major point people need to focus on.

I think, to bastardize a famous quote, that testing is the worst simple measure of aptitude, except all the others we've tried. In a perfect world, any admissions/hiring decision would be made after multiple independent in-depth examinations of a candidate's past work, plus extensive interviews. Since that level of vetting is unfeasible for all but a tiny sliver of the most desirable spots, we need ballpark estimates like testing that will be more predictive than coin flips.