I am in complete agreement with Mr. Bennett on the matter of the Mirror Universe being referred to as such in-story. Not to mention the matter of turboshafts as "a roller coaster in an industrial hammerspace" (clever turn of phrase -- have you ever considered a career as a writer?) Be afraid. Be very afraid.
The Turbolift Funhouse doesn't bother me in the slightest. Actually I find it refreshing that they do things like this just because it looks cool! And I can't say I'm bothered all that much about the term "Mirror Universe" being used onscreen, because that's exactly what it IS. It does kind of irritate me regarding "Terran" as a species name. They're just as human as anyone else, they just ACT different...
What bugs me more is how they treat "Terran" as a name exclusively descriptive of Mirror Universe humans, when it applies to Earthlings in any universe, including ours.
Yes, that annoys the heck out of me too. Almost every previous Trek series used "Terran" to refer to people or things from Earth, as science fiction has been doing since at least the 1940s. So DSC's use of it as a specific, exclusive identifier for Mirror humans is contradictory and bizarrely unaware of prior usage. Indeed, even Mirror episodes didn't use the term "Terran Empire" until ENT: "In a Mirror, Darkly" (though it had been used in the Shatnerverse Mirror Univers trilogy before then). When DS9 first started having Klingons and Cardassians refer to humans as "Terrans," I think it was probably meant to represent a term that aliens used for humans rather than one they use for themselves, which is how it's often used in science fiction. Sort of like referring to the Rom people as "Gypsies," say. So I think it's missing the original intent to reinterpret it as Imperial humans' name for themselves. They went even further a few episodes ago, though, when Emperor Georgiou twice called Dr. Culber "human" as a derisive epithet, as if she didn't consider herself human. That's ridiculous! Of course "Terrans" are human! Not only have they always been called that in previous Mirror episodes, but if they were a different species, they obviously wouldn't have the same individuals.
Whose to say Georgiou considers herself human? She certainly would see herself as superior in multiple aspects to her prime universe counterparts. Who not use the term with contempt?
I don't believe that's what the writers had in mind, though. Remember, this show has also claimed that Mirror humans, or "Terrans," have a physiological difference that makes them sensitive to bright light (although that doesn't seem to be an issue for Georgiou). So they've claimed before that they're biologically different, as nonsensical as that is.
Maybe the mirror universe did not have a problem with genetic enhancements once Khan came onto the scene. Hence the eyedrops; experiments in genetic enhancements altered their eyesight in a way that never occurred in the prime timeline, where there was not an interest in genetic enhancements.
Which would be fine if not for the fact that they still have all the same individuals being born 400 years later.
I mean, I haven't seen the immediate issue for the sensitivity to bright light, at least so far as Star Trek science goes. It's not the most nonsensical idea to appear in terms of creating some measure of biological difference between apparent human species. Also, even if it is a biological difference it probably isn't going to show up the exact same for everyone. At least, that make sense to my basic understanding of genetics. But, that's me. It's a simply story idea that I am willing to go along with, even if it doesn't make perfect sense.
"Mirror" makes sense since to the people in the world, it's a dark reflection of themselves. "Prime" makes sense because with various other universes out there, you need a way to refer to yours. And "Terran" just takes one leader to ram that name down everyone's throat and it becomes it.
Because they are not a different species. How can an alternate version of James Kirk or Jonathan Archer or Benjamin Sisko or Michael Burnham not be human? It's a contradiction in terms. And of course, every previous series that featured the Mirror Universe explicitly did call them human in dialogue, even aside from the obvious fact that they must be. Just as Mirror Spock was explicitly Vulcan, Intendant Kira was explicitly Bajoran, etc. It's an alternate timeline. Same planets, same species, same individuals, just with a different history. The problem is not that Mirror humans call themselves Terran. The problem is that Discovery thinks prime Earthlings are not called Terran, when they explicitly have been over and over again in almost every previous Trek series. "Terran" is just a pseudo-Latin word for "Earthling." Anyone from any version of Earth is a Terran. So it makes no sense to treat it as some exotic alien term used exclusively for people from a parallel universe.
It could be that the Disco took how Mirrorverse people refer to themselves to heart and started using it exclusively that way to differentiate. They're quite an accommodating bunch.
That doesn't change the fact that it's a continuity error when characters hear the word "Terran" with no other context and immediately understand it as a reference to Mirror humans exclusively. That implies that the term was never previously used for Prime Earthlings, and we know for a fact that that isn't the case (see "Yesteryear" when Sepek insults young Spock by calling him a Terran -- or "Tur-Ann," as Keith Sutherland pronounced it).
It was both. "Earther! Barbarian! Emotional Earther! You're a Terran, Spock. You could never be a true Vulcan."
When the term "Terran" was used on DS9, I saw it as a thinly veiled insult. Meaning: The Klingon/Cardassian Alliance routinely referred to humans as "Terrans" as a not-so-subtle reminder of how the Terran Empire has fallen, and that humans were now slaves. A way of reminding humans that they should know their place...