Well said. That attitude "they must be a fake because I think so" can manifest in vigilante behavior, questioning, harassing and reporting the supposed "fakes." The kids on YouTube call that "Karen" behavior, "the policewomen of all human behavior." I am waiting for a Karen YouTube video where an angry cruise ship passenger harangs the hapless owner of a legitimate service that isn't a German Shepherd with a harness--or too small (or cute) to be a "real" service dog. Or one where the dog owner tells the "doggie police" it's none of her (or his) business and the "Karen" summons the ship captain. Those videos often contain the "karma" moment where the "fake" is revealed to be not fake and the accuser looks like an entitled, holy-than-thou busybody.
I have looked, but I haven't found any cruise ship "fake dog Karens," but that might be because a) I'm no good at Google, or b) the problem is not so widespread that there are few opportunities for "Karen at sea" videos.
Okay, you can now line up to tell me I'm wrong, uninformed, rude, etc.