@LadyMeowMeow - I would submit that you, I and the staff of the Harvard admissions office can tell an awful lot about someone from their activities outside the classroom (including any leadership roles or special achievements), personal statements, recommendations and interview, coupled with their academic/testing record. You or I (and, no doubt, many others on this forum) might even feel that we’d be good enough at it that we could hold our own with the finely calibrated BS detectors that long-serving Harvard adcoms and their peers have developed over many years on the job. In other words, I think we’d all feel like reading someone’s admissions file would give us a reasonable sense of their “character”.
I think there are three difficulties, though:
First, not everything is revealed in those files, and inevitably a few not-so-nice people will slip through the net when an admissions office has to review a consistent set of information from close to 50,000 applicants every year, no matter how experienced the adcoms are. It’s not practical for Harvard to commission a full background investigation on everyone they choose to admit - and, even if they did, they still would get some wrong. I’m not sure what you think Harvard should be doing differently.
Second, many Harvard students have one or more prodigious talents, or are highly accomplished in some way. That’s a large part of why Harvard wants them. Sometimes the price of great accomplishment and the effort it requires is some other kind of personality distortion that may not be revealed in the admissions file but may eventually manifest itself in ugly ways.
Finally, and most importantly, I’m unclear as to what you think constitutes good character, and why you think Harvard is incapable of reliably identifying it. Somehow many Harvard graduates - more than at most places - go on to accomplish great things in many spheres. That, I would suggest, takes more character than most of us possess - but some of those people are also not-so-nice. Some Harvard graduates never become rich or famous, but do wonderful things in comparative obscurity - which also takes a lot of character. Harvard looks for those kind of people too. Some are fine spouses and parents - same thing. Some don’t fulfill their promise, or are wealthy wastrels. Maybe Harvard got those wrong - but they get lots of people spectacularly right.
It sounds like your issue is that Harvard “cannot guarantee the slightest thing about morality”. Of course they can’t, because no one can. They couldn’t do it even if they tapped the phones of every kid they admitted and had them followed by private detectives. They never claimed that they could, though.
For a close-to-home, real-life example of why I think your arguments are inapplicable to the world as it actually exists, I invite you to consider the case of Ken Griffin, Harvard '89, CEO of Citadel, one of the largest hedge funds in the world, which he founded a year after graduating from Harvard. He has been enormously successful, and is a billionaire, but is not warm and fuzzy, not at all, as this article will make plain: http://pagesix.com/2015/01/20/richest-man-in-illinois-accused-of-bully-tactics-in-ugly-divorce/. What do you think of his character? What do you believe Harvard thinks, or should think, of it? Is it great, because of what he accomplished, or not-so-great, because of how he seems to have behaved in this instance?
Now, consider that in 2014 he gave $150m to Harvard, the largest gift in Harvard College’s history at the time, to be used for financial aid that would impact 800 undergraduates a year, and Harvard named their financial aid office after him. What do you think of his character now?