What do you think of people who refer to Linux as Unix

I work at a big well-known corporation where I noticed that people will say “Unix” when they’re actually talking about Linux. We don’t have any Unix servers but we do have a lot of Linux so I’m wondering why they do this, and it’s kind of annoying. Does anyone here do this? Why do people do that? I think that maybe it also goes against the GNU philosophy and that that acronym is basically saying don’t refer to Linux as Unix.