A few months back, there was a big fuss about people calling others NPCs, after the non-player-characters in computer games, who mostly either follow the player around, or just stand there to answer questions from the player or look pretty.
Obviously, the usual suspects whined about how awful this idea was and everyone is an equally unique snowflake and… whatever.
But, when you think about it, we have no problem believing that animals aren’t sentient and humans are. So, somewhere between a rock and a human is a point where matter goes from not-sentient to sentient.
Why, then, is it hard to believe that might apply to people, too? That some are literally not sentient. It’s even backed up by psychological studies which have shown that some people have no internal monologue, and merely exist.