Whether you agree with it or not the discussion is in regards to Emet-Selch's views on the Sundered.
Alisae speculates during the MSQ's that she would probably seek to do the same thing were she in Emet-Selch's position.
As was pointed out in a prior post...
Gaia was irrelevant to Mitron's goals. His concern was Lohgrif, who he had made a promise to reunite with and she had accepted. Gaia is not Lohgrif, thus an obstacle he sought to overcome. You're correct in that he didn't ask her permission or try to reason with her. Yet the same can be said of the countless lives that the Scions and Warrior of Darkness have ended for mere differences in opinion/political alignment.
Ultimately, it was framed as a tragic love story. Gaia survived, Mitron and Lohgrif did not.
None of the victories against the Unsundered are without convenient tools to gain an edge. Against Lahabrea, not only had he been weakened by body hopping but Hydaelyn expended energy to protect against Ultima.
Against Emet-Selch, the battle was framed as exceptionally hard fought. Even the usual trick of white auracite did not work and G'raha summoned combatants to aid in the fight. In addition, Ardbert had to merge with the Warrior of Darkness to provide yet another edge.
As for Elidibus, it was once again a hard fought victory and the power of the Crystal Tower was expended in order to effectively seal him away.
I believe this is a good opportunity to remind you of this post on a previous page, as it deals with the subject of the Unsundered and how they may very well still be around in some form:
https://forum.square-enix.com/ffxiv/...=1#post5566422
The development team have stated repeatedly in a number of interviews that it is a matter of perspective. Individual characters argue in favour of what benefits their respective causes but that...should be a given.
I personally think that it is indeed a settled matter in the context of the game's story, which many of us are here to discuss rather than matters of morality.
Speaking of the game's story, here's a snippet of the journal entry for the battle against Emet-Selch:
You wage a titanic battle not only against Hades, but the hopes and dreams of Ascian-kind, of which he is the keeper. In the end, however, your own unwavering conviction brings the ancient being low. You have done a great and terrible thing. Pen the conclusion to this momentous chapter of history, and make your return to the Ocular.
Source: https://ffxiv.gamerescape.com/wiki/S...ingers#Journal
It is quite clearly framed as a good thing for the Scions and Warrior of Darkness but a bad thing for Emet-Selch and his people. Which...makes sense, given that each were heroes with opposing causes and a firm desire to do whatever it took to protect their loved ones.