As someone who's travelled 10,000 mile round-trips for final interviews, only to lose out on "culture fit," I find it the most frustrating excuse for not getting a job I have otherwise proven over previous interview rounds that I am capable for. Why? Because it's totally unquantifiable and subjective. Fair enough if you find a hole in my technical ability which would limit my performance in the job you want me to do, but using "culture" as the excuse is a nonsense.
There could be any number of reasons someone might not appear to "fit" on a given interview day, which wouldn't necessarily apply in them in the day-to-day - jet lag, the stress of the interview process, being under the weather and many more...
People and cultures adapt over time, through contact with each other; if you're denying good candidates because of their "fit" in the now, you're artificially limiting yourself for the future.
There could be any number of reasons someone might not appear to "fit" on a given interview day, which wouldn't necessarily apply in them in the day-to-day - jet lag, the stress of the interview process, being under the weather and many more...
People and cultures adapt over time, through contact with each other; if you're denying good candidates because of their "fit" in the now, you're artificially limiting yourself for the future.