>Harvard is happy to churn out a nonzero number of students wholly unprepared for meeting extremely basic expectations for the prototypical job of their chosen degree
From one of my professors who did their graduate work at an Ivy, apparently there are a lot of rich kids who can't be failed because their parents donate so much money to the school. But I don't think Harvard has ever had the best undergraduate reputation (among the Ivies), its more well known for its grad/professional programs.
From the people I know that studied at places like Harvard and Yale (which since I'm Canadian isn't a huge sample size), I've been told that there are essentially two different streams of undergrads there - those on legacy admissions and those who qualified otherwise (either via brains, affirmative action, or other means). I was left with the impression that the legacy admissions are mostly people who've coasted through life. The rest are a full spectrum of people.
Most of Harvard's endowment is via alumni, so it doesn't surprise me in the least they continue with it.