And why the heck would a kid in band go to Harvard? He should be getting in a van and going on tour. And why would a kid in the chess club go to Yale? He should be playing chess. And why would a kid on the baseball team...

The typical over-achieving student is going to be in dozens of activities, none of which necessarily correlate with their future career. Agriculture might seem really weird or foreign to you, but for much of America being in FFA/4H/Eagle Scouts/whatever is just as normal as band, chess or sports.