Of course that was the reason he was rejected. Companies do plenty of stupid and/or illegal things, they just think they can get away with it. Just look at Theranos. Or banks wilfully working with drug dealers to launder money. Or Google and co making agreements not to steal people to keep wages down. It's all about risk management.

And yet, Harvard and all the Ivys do it all the time.

Not in 30s.

Having some undesirable demographics myself, I'm quite aware that corporations discriminate illegally. It's so easy to hide, though, and so costly not to do so, that imagining this as an example seems a bit silly.

It’s definitely not “absolutely zero”.

Sure, in the same way -450 degrees Fahrenheit isn't technically "absolute zero."