Well there’s a cost to diversifying your workforce when it’s culturally homogenous. Communication barriers are in place and it’s easier to blame the outsider who’s targeted by them than it is to remove them, so “culture fit” is often a very practical concern that can literally just be boiled down to, “they would be hard to work with” in the minds of interviewers. For truly upper class environments, it’s somewhat reliable to talk to someone about whether they do freshwater fishing or deep sea fishing and take that class marker as an indicator of fit. (At least I think those are the class-differentiates types of fishing. I’m not wealthy enough to own a boat either way)