Most people are going to college hoping to get a job. They're learning because they're told they have to learn, so they do a bad job learning. In a field like civil engineering, you can't graduate unless you pass classes that are simply unpassable without learning some stuff. (I have a friend going through aerodynamics right now and I'm hearing about everything he's learning.)
This is kind of a microcosmic version of what we're seeing in general: we see people as workers first and human beings second. The universities and the kids are following suit.
Then we created secondary/"grammar" schools. The children who attended them surpassed their peers, who had only attended elementary school. Employers began to require a secondary-school education as a signal of competence. Eventually, being such a "universal good", secondary education became a public service of the state.
Then we created universities...
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Although the inductive step is valid, there's a problem in the assumptions: we already had universities for thousands of years before the introduction of elementary or secondary education!
The traditional "liberal education" of The University, where the upper-class and the cunning go to cloister themselves with one-another and thus boost their mutual productivity in all sorts of status-signalling arts (sounds sort of like TED, doesn't it?) has come crashing head-first into the rising bar of minimum-expected human competence. Success in secondary school no longer tells you anything about a person's class or cunning, and that's forced employers to look for increasingly-lofty-and-meaningless trust-signals. So "everyone who's anyone" expects to go to university now, from the spoilt valley-girl to the farm bumpkin.
Perhaps, in the end, if we want to preserve the "usefulness" of university, we'll chop off the undergraduate portion of it and call that "tertiary school" or something. Everyone gets to go, it occurs at community colleges, probably most of the material comes from Khan Academy and the like. Then the rich and the cunning can go to The University after that.
I'm really not sure who you're addressing. No one is claiming these assumptions.