Yield calculations have a lot to do with legacy admission rates.
But to be clear: I'm not trying to claim that there is no legacy preference and that it can be all explained by test scores. It is definitely a big factor.
The only two points I was making is that 1. traditional "legacy" admissions is not necessarily the route that a lot of students without any merit are getting into these top schools - they often have separate pathways for donors and super elite individuals, like Harvard's "z-list."
2. Legacy admissions are because schools know that if they admit more legacy, they will get more donations - but it also has to do with calculations about selectivity. Harvard wants to maximize the chances that the people it admits will choose Harvard so that they don't have to admit more people to fill the class thus raising the admission rate.
And your clarifications really don't address that, and you even seem to back away from it now. Why even make the absurd claim about the intellectual and test-taking superiority of legacies over the peasants if it isn't significant - as you're now claiming?
All I wanted to clarify is that these legacy processes only really come into play once you have already hit some minimum threshold of merit, and there are different backdoors for super rich/connected applicants that require no such threshold.
Tests are not the same thing as intellect - they are often structured in a way that is unfair to people with low incomes (for instance: the more times you pay to take a test, you can then select the top scores). All of these are pathways that would still exist without legacy.
You're construing my comment as taking a stance that it wasn't - but in case it wasn't clear now, legacy admissions are unequivocally bad. Privileging class status in admissions is obviously bad.
A legacy with a 1600 has a substantially higher chance, due to their parents alma mater, than a non-legacy with a 1600.