Earlier quoted context omitted.
I've always preferred "Terra" or "Gaia" to "Earth." It could be a preference from video games, or maybe it’s because the common usage and being a synonym for ground and dirt has made the word seem ”low-brow” and the alternatives classy, exotic or poetic, and if their popularity was reversed we would think "Earth" was a classier word, but still. “Terrans” will always sound better than “Earthlings” however. :)
I think this is just one instance of a near-universal perception among English speakers that Greek/Latin words ("Terra") sound more sophisticated than Anglo-Saxon ones ("earth"). It's hard to hypothesize about whether this could be reversed in an alternate universe because this tendency goes back many centuries: for a loooong time Latin was the language of the scholarly and political elite, whereas Anglo-Saxon Old En…
French was too for hundreds of years even up until now and maybe for the EU again after Brexit.