They have enough smart alecs to make it as scientists and engineers in NASA and large corporations where such skills are needed. For their local social skills, ability to present oneself and conduct one's image in a social setting are more important. In any case, why would a professional football player need to ace exams in mathematics and/or literature? Or a rock musician, or a truck driver? Or a cocaine dealer?
Cheers!
the rocket scientists and quantum physicists will succeed despite the appalling public school system. good motivated students will succeed regardless of their schools/family backgrounds/social circumstances etc. give them the lousiest teachers and they will still seek out knowledge on their own.
then there are the middle band of students, those who need some handholding and guidance to bring out the best in them. this is where good teachers really shine in bringing out the best in what seem like average students.
finally there are those at the bottom, who need the most intervention and the best teachers to even give them any hope of life beyond prison, gangs and dish washing (albeit dish washing now pays $3k/mth)
education will benefit everyone, including rock stars, musicians, actresses, entertainers and even cocaine dealers. most especially cocaine dealers as they will be the most likely to get entangled with the police.
IF the purpose of streaming were driven altruistically by the desire to better allocate good teachers to weaker students, then streaming would be a good thing. unfortunately because of streaming as we know it today, weaker students are denied access to the limited supply of good teachers. ideally all teachers should be good, but in reality we probably have a bell curve of good to bad teachers.