That is only if you focus on the curriculum covered in SAT. If you instead see SAT as a proxy for the eventual success in the society, then I believe SAT is a g

That is only if you focus on the curriculum covered in SAT. If you instead see SAT as a proxy for the eventual success in the society, then I believe SAT is a great indicator of the factors which lead to this success - family wealth, willingness of parents to invest in their children, diligence and rote work required to ace such tests, ability to find loopholes to strategize and game the system (we love "hackers" here, no?) etc etc. In other words, if someone is going to succeed because of SAT, they will succeed even if you remove SAT from the picture.