The real counter is because it’s not fidelifaux: that is, it does not feel “true to the false” or “faithful to the fiction”

same reason why having the USS enterprise show up in Game of Thrones would be ridiculous, or for more subtle examples, why modern social etiquette / modern gender relations would feel off in Lord of the Rings, Why it would be ridiculous for Star Wars characters to be playing a Call of Duty shooter— none of that feels true/faithful to the fictional world that’s been created.

fictional universes rely on internal consistency or else you end up with a world that feels non-deterministic, and thus, uninteresting.