Thermonuclear take; the kind of work it takes to perform well in school is exactly the kind of work society is preparing kids for, so good school performance can still be a strong indication they'll be good employees.

Wether or not our society and schools are right for that is a much more interesting topic of debate. Kids who crush it in school (and continue to crush it all the way through college) will go on to make their companies loads of money for cheap.