On the other hand, "they would not have been a good fit" sounds suspiciously like a blanket, non-falsifiable denial of failure. I other words, bullshit.
See also: "you don't have enough experience," one which I most recently heard myself after four interviews and a technical assessment, in which my (passing) solution included a bugfix to the test itself.
"Culture fit" has become like the currency of recruitment. Supposedly what you may have to pay with for a potentially great engineer (technically) about whom the hiring team didn't feel comfortable with. I think the original question is a great one. Do we actually put these intuitions to the test?
