Yeah, and it's not necessarily mobbing to only tell people you really like about your party. But where it occurs, people never admit it to themselves and justify it in such a way, so that justification is meaningless. All wars of aggression are called a defensive emergency measure. Hundreds and thousands and rarely would anyone say "we'll take this because we can and you're helpless". No matter how glaringly obvious it is, it's never admitted.
In the same way, I can acccept "cultural fit" as a summary of things a person can describe, sure. But I think more often than not it's just a thought-terminating cliché. It can also just mean "I cannot verbalize my reasons and/or don't want to admit to them".
You can say if something fits only if you either can describe both sides in sufficient detail and where it wouldn't fit, e.g. a plug and a socket. But if it's dark, you barely see anything, and just have a "hunch", then "fit" doesn't even apply. It's like telling someone you won't let them through a door because they wouldn't "fit" anyway -- okay, so let them try, if they actually won't fit you don't need to read tea leaves and gate keep based on that.
Preferring to go with a more safe and familiar and obvious candidate, fine. But don't pretend it's because the others won't "fit".
Culture, in so far as it deserves the name, shapes the people exposed to or in it, as well as the other way around. E.g. if only people who fit the culture can work at a company, no company can exist in the first place, because for there to be a culture there need to be people there. So that leaves setting the culture in stone after it grew to a certain size, and only looking for more of the same, which also isn't great, but at least still honest.
If a culture is so brittle it cannot integrate people who aren't already a product of it, that may be a legitimate choice of the company, but my assessment to find that lame is also valid.
I feel the same way about immigration troubles, tangentially. We moan because people we don't actively try to get to know don't care for our rules which we don't enforce in a confident, but respectful manner. We basically require sterile, bland input because we have no immune system worth speaking of and no way to process and refine what comes in.