A dumb thing Zuck said when he was in college pales in comparison to the horrible stuff he's enabled as a fully formed adult who should know better.
But there are things you say as a young person that are revealing of core personality traits.
Most people would just not say that.
College is where things start to firm up for most people, though. I don't think I've ever known anyone who was a terrible person in college who turned out good.
The thing he said in college was shitty, and indicative of a spoiled, entitled, child of wealth and privilege, but saying it was basically harmless. Worse things might be said at the corner sports bar on any given night in any city in the country.
What he's done since has caused real harm.
"A" dumb thing
Ignore dumb fucks
What about "if you need info on people at Harvard just ask"
Or "I'm going to fuck them in the ear" (Winklevosses)