This is myopic almost to the point of satire. You really can't think of a single other benefit of social intelligence?
But you get graded based on your ability to read, write, do math, memorize data points. Not on your ability to lie to your teacher in a believable manner.
You may excel later in life, but it's not like you can enter Yale because you can manipulate people.
You also need a certain level of other intelligence to properly manipulate people, or at least a certain level of self narcissism.
I mean you kind of proved my point, perhaps we should be teaching/discussing social skills.
I completely agree that social skills should be emphasized in school-not to reward the people who are already adept, but to impress on the others that they're the primary determinant of success.
It's incorrect to think that's limited to America. Humans are mostly powerless against the charm of narcissists and other sociopaths.
You see it over and over throughout human history all over the world.