This was something that irked me the entire way through.

None of the Scions acted like themselves, and I genuinely believe it's because they're incredibly well written characters, who are, as a result, very difficult to properly write for someone who is lesser skilled

(Alisae is usually my least favorite Scion, but in DT, she was my favorite character, and I think that's just because she was the Scion who felt slightly less like a knock-off brand of herself, than everyone else)

This expansion had a massive fucking treasure trove of simple storytelling/writing failures, and it relied on some of the most overused and uninteresting archetypes/cliches to portray it's characters/plots. It had extremely infantile, irrelevant, or just blatantly wrong philosophies and morals. And where it didn't reuse story tropes that are frequently found in children's shows, it instead tried to rehash and reuse the selfsame story beats that previous expansions had used. The entire thing with Sphene was just Emet-Selch's story done incredibly poorly.

The main villains made no sense and were extremely unthreatening, and when the expansion began to stretch on to the final ~30 quests, and the writers realised they're written the entire thing up to that point with filler, they tried to force in some kind of emotional substance by enacting pacing far worse than what your average 12-episode Netflix anime employs. The attempt to brute force us into feeling anything at all just came off as obnoxious and insulting, like the writer genuinely expects to be able to play some shitty music track or make the player choose between three god-awful Marvel movie quips, and then have the viewer feel anything other than second-hand embarrassment for playing the game.

It was all terrible, and I think it's in large part due to the team in charge of writing the MSQ being pitifully under qualified for handling XIV the story they were given, and the localisation team for the English version as well, did an absolutely terrible job. I've been told that the stupid quips, weren't quite so insufferable in other languages.

So with all that said, it's not at all surprising that the characters were acting like cardboard cutouts with "plot-device" written on their backs, instead of feeling like human beings.