I'd rather bet on inconsistent overall production, as the big business decision was probably introducing Wuk Lamat and twisting her to better fit the obnoxious thing we've seen.
The whole trans-audience thing was probably a factor there.

But even so, there are multiple failures so heavy they couldn't have been allowed to happen in a mature writers' cabinet, and I don't think a single person would create this much of a mess.
We have to look at the incongruous scenes, underdeveloped conflicts, Galool Ja Ja being a man-child instead of a reptiloid version of uebermensch...
The rehash of the messages from ShB and the repetitive approach to such messages, lack of any interesting new messages (and the thread that should have been interesting - unifying of multiple cultures with varied degrees of force and guile, reminiscent of Di Zhengshi and Czhenghis Khan, with all of that approach's excesses and victories -- is not examined at all, neither in DT nor in EW's Garlemald)....

[SPOILER] Even Stormblood which I frankly found tedious, incongrous and overall abhorrent, was very, very solid in this regard. Apart from impostor-syndromed Lyse we had collaborationism examined properly, if superficially, we've had a narcissistic woman who'd been pushed into the role and life of a monster and was, to a degree, reformed by the end of her life, the thing about a criminal without memories not being able to properly handle the resentment towards them...

In ShB we've had a whole treatise on the dangers of indolence and hedonism, on people needing their skills to be called upon to actually feel useful and happy. We've had a single man's determination to correct the course of history so strong he actually broke the whole previous lore of the game (and common-sense logic of it all) in half. We've had a certain crippled gunbreaker face a sadistic lifebreaking dilemma of taking an innocent life to be reunited with the one person he loved and lost, and that was almost examined properly. And we've had Ardbert, et al, oh, we've had Ardbert, who single-handedly served as a lynchpin to the whole story and made it work dramatically while being a side character without power to influence events... and that's where we learned what the dead might have felt, had they existed as he did. And good old Emet would simply not have carried it all, were it not for Ardbert and his prior impact on the world.

Of course, both those expansions had their faults and their fair share of crap.
But not nearly on the level of DT. [/spoiler]

I could go on and on. But out of all the things we've seen I can highlight one general feeling -- the tone of DT - indeed, the tone of every single part of DT - is off. Sometimes slightly, sometimes very much so, but always off. So there's now a failed expansion, and we would like to understand what actual conclusions SE have drawn from that.