The story doesn’t say whether they were wearing the earring while being interviewed

Is there more than one of these earrings? The rest of the story makes it pretty clear that it's a singular artifact. If so, and given that the other wearers certainly weren't dead when being interviewed, the only explanation is that some people just decide it's not for them and take it off. Leaving out the qualification "living wearers" would have left some wiggle room, but that's not what the text says.

It's one of those stories that sounds profound only until you start to ask questions.