But let's not pretend that Ivy League school operate on anything resembling merit. The reason you want to go to those schools is not their top-notch academics, which you can get that in many other places, but as a shortcut to the old-boys networks. Unfortunately those old-boys networks don't serve as patrons out of the goodness of their hearts, so they require that many of their otherwise unworthy offspring to get admitted.
It's a tough nut to crack. If Ivy Leagues started admitting based solely on merit, they'd lose much of what makes them desirable, hence they need to add vague criteria so admissions personnel can safely discard and let in the right people.
Basically, Harvard is Harvard not because the exams are tough, but because the scions of the rich and powerful go to Harvard. So how can you have both the scions of the rich and powerful go there AND admit people based on merit?