> The ones joining frats, partying constantly, playing sports and all that must have trivial classes. Either that or they’re already so rich and privileged that they can afford to fail courses and keep going.

I don't know why you're assuming this, but I'm a little insulted. I was an NCAA athlete and a common refrain I always heard was that the most valuable skill you get from it is incredible time management. I didn't kill time on sites like HN or reddit or facebook (the only social network at the time). We partied a decent amount too. About half of the particular people I played and partied with now have doctorates from world class institutions. Nearly all of us have STEM degrees.