In my experience "Candidate X isn't a good cultural fit" has almost always been used as short had for either "I don't want us to hire them, but I can't articulate why in way I am comfortable with" or less often "What an asshole". I don't think I've ever been part of a conversation about "cultural fit" that wasn't swimming in bullshit, or at least wading in it.
A big classifier I've seen that gets put under "cultural fit" is the "it's not my job" problem. A startup can't have people saying that, but big enterprise companies live by it. Some people just can't transition from one to the other. I've found in interviews that some people expect to do exactly what their credentials have prepared them for. At least for the places I've worked, that's insufficient for programming an…
Hiring for a startup : "They seem like more of a big-company type"
Hiring for a big company: "They seem like more of a startup type"
It's not really company specific.