A good example of why well educated parents is more important than getting into the "the best schools".
Isn't that just a matter of chicken and the egg timing tautology? The parents are well educated presumably because they went to good schools.
I think a good education is more about the student than the university. The reason for the strong correlation to the contrary is because good universities get to hand pick from those overachievers whom would achieve with or without said university. And that character development happens long before one's applying to universities.
That said a top university, its resources, and atmosphere of being surrounded by other top students, certainly helps foster even more success - but I expect if you take the average merit admitted MIT student and transplanted them into Party State U after 4 years you'd still find an extremely 'well educated' individual. By contrast, transplant your average Party State U student into MIT and you'd find a dropout.