Not sure whether “pure numbers” serve as the best measure of “merit.”
You would have to factor in more subjective considerations such as strength of curriculum, strength of school, etc. to put the numbers in context. Also, top-notch SAT scores are somewhat meaningless because far more people attain near-perfect scores (around 1500+, out of 1600) than there are places available.
Extracurricular achievements are important because they tend to distinguish students who are able to do well academically while balancing other commitments (as well as more well-rounded individuals generally) than those who merely study to get good grades and test scores. Essays and recommendations are used to assess an applicant’s writing abilities, work habits, and intellectual curiosity. Pure numbers do not necessarily or accurately reflect these attributes.
For the most part, the students at Yale (and at Harvard, Princeton, etc.) have the “merits” to be there. Whether they take advantage of the enormous opportunities there or end up with common sense views on politics, economics, etc. is ultimately up to them. Many students tend to be liberal, but they are not the “social justice warrior” types who seem to grab all the headlines.
Unfortunately there are those (probably like the ones dissing the professor) who got in primarily on Affirmative Action or other similar programs. Judging from the sight of these kids, I am guessing that today's colleges have become the equivalent of high school. They all seem beyond immature -- they have a chip on their shoulder.
When I was in college, I felt like kid compared to the students around me. They were intellectual, self-assured. The ones at Yale & "Mizzou" seem like a bunch of misplaced street kids.