Excellent article by Outook Zen: The Real Truth about NYC’s Elite High Schools
A many have already noted, the left cares more about equality of outcomes than equality of opportunities. The left cares more about equality than helping the gifted and talented poor.
According to the left, east-Asian, east-Indians and other high-achieving groups don’t count as ‘diversity’, whether it’s Silicon Valley or elite schools. As soon as a group becomes too economically and or academically successful, they stop being useless shills/pawns for the left’s egalitarian ideology.
If ‘victimized/oppressed’ groups score lower than non-oppressed groups on such tests, according to the left, the tests must either be done-away with or made so easy (or so hard) as to be useless at identifying exceptional talent. That could explain how the SAT has become progressively easier with each iteration.
And despite this stunning breadth of socioeconomic diversity, Stuyvesant is also one of the most successful high schools in the country. Boasting a 100% graduation rate, average SAT scores of 2170, and 4 nobel laureates among its alumni. Whatever the school is doing, it’s working. It takes in some of the poorest and least privileged students in the city, and churns out successful graduates with bright futures.
Are they succeeding because of the school or because they are selected for high IQ? I suspect it has more to with the latter. But that doesn’t mean elite schools such as Stuyvesant are useless, because elite schools have resources that allow America’s best and brightest to live up to their full cognitive potential, such as through access to special connections, laboratories, enrichment programs, and AI and robotics labs, etc that regular schools do not have. All else being equal, a high-IQ poor kid attending an elite school has a better likelihood of success than at a regular school. 
In contrast, the admissions process for getting into Harvard is one of the most opaque and subjective imaginable. It rewards those with impressive family connections. It rewards those with parents who also belong to this exclusive club. It rewards those with families that are rich beyond compare. It rewards those who are wealthy enough to afford an impressive array of made-for-college extracurriculars. It rewards those who fit into the mold of glib, attractive, extroverted salesmen, and punishes anyone who doesn’t.
Harvard also selects for high IQ, but the problem is, despite this, the number of qualified applicants vastly exceeds the number of available slots.
 But doesn’t that justify more spending for better schools, overall, regardless of IQ, if everyone benefits (even if very little)? I suspect the marginal benefits and ROI for high-IQ enrichment are higher. As adults, high-IQ students create technologies, research, and innovative companies; low and middle-IQ people typically don’t. Enrichment programs for low-IQ kids (or simply special ed) to get them ‘up to speed’ seems like an inefficient use of public resources that could otherwise be spent on kids who are more likely to produce economic value.