This is totally anecdotal and by no means scientific: I have heard more than one case that U of C takes not the highest stat in the class but the smartest albeit eccentric/quirky one. I can see from the parent’s perspective this rejection particularly stings because they feel U of C accept a kid with worse stat but their own kid has to suffer the humiliation of losing to an “inferior” kid. However, from the cases I know about the rejected students do not feel bitter because they recognize the admitted classmates are equally smart as (if not superior to) them but the admitted students just have worse stat.
I think by now all the parents for kids at the college admission game should ( I repeat SHOULD) realize just because their kids having higher stat in no way implies that they have better chance of admission than their classmates with slightly worse stat. AO is looking for future potential of the admission candidates and NOT just the test scores and GPA. For Nondorf and his team, my guess will be they are looking for an intellectual and bright kid who is willing to put in the hard work to understand much deeper about the subject matter. The journey may be tortuous on the way but in the end the U of C college students would feel more empowered and enlightened than going to many other schools they could have gone to.
P.S. I know some current college students may strongly object to the above statement. But sometimes you have to wait 10 to 20 years after graduation before you can look back and assess the impact of an U of C education on you. Please listen to David Brooks opening comments in the recent IOP lecture.