First, it was suggested that this test should be used for programming job interviews. Second, why would a school who teaches programming care if students had programming ability? If you answer it is because the school wants to maintain a reputation of producing good programmers (hence adding value to the students' resumes), it contradicts your statement that this test is a better predictor than a resume. Otherwise, people would just study algebra instead of going to that school.
The author uses it as a predictor for acceptance at a school.
For the way, he was around the thread explaining that he can train a limited number of people, and that some of them not learning is wasteful and uninspiring.
First, it was suggested that this test should be used for programming job interviews. Second, why would a school who teaches programming care if students had programming ability? If you answer it is because the school wants to maintain a reputation of producing good programmers (hence adding value to the students' resumes), it contradicts your statement that this test is a better predictor than a resume. Otherwise, people would just study algebra instead of going to that school.