I had to go back and rewatch it upon you reminding me, and the whole scene was as staggeringly awful as I remember (damn it, Midare, I'd almost managed to forget that "I bid them remember, but I'm the one who forgot!" line!) Apologies to the people who enjoyed it and found it moving, but good god, the entire scene was Emet's characterisation bouncing around the scene like a yo-yo so the writers could make use of his popularity and make him their mouthpiece. The almost gentle chiding of the woman who caused him to suffer absolute misery, the lighthearted buddy cop show banter between him and Hyth during the supposed emotional highlight of the entire series when everything they've fought and sacrificed for is at stake, those endless godforsaken theatre kid puns that should have died with Emet's Garlean facade and the subtle justifications for the nebulous story, claiming mortals had fared better than anything they could have achieved...
But to focus on that line in particular, because it is the most interesting - I do distinctly remember feeling very ??? upon hearing it, because I wasn't actually sure what the writers were trying to get at with it either. The first part, I actually really like as a stand alone quote - it feels very much like the Emet we defeated at the end of ShB, and the poignancy of that "and why I lost" line is beautifully heart-breaking, as if he's admitting aloud for the first time what we knew, but he had never allowed himself to think - that his heart had gone from the fight, and he had lost the will to continue. They could have ended it there.
But the ideals part baffles me. What ideals? Did Emet have ideals? I thought he was painted as a "by any means necessary" kind of guy adhering to his duty who had little regard for principles, morals, notions of good and evil - he frequently resented being seen as a villain, and seemed to view to everything through the lens of "is this useful to me?" rather than anything else. His ideals that the Ancients were superior? That the world should have been rejoined? As you say, were they genuinely trying to shoehorn in a quick "I don't regret any of the suffering I caused" in the same moment they were trying to make him a grudging protagonist?
The kindest interpretation I can give is him referring to his sense of duty to his people, meaning he would always have done whatever he could to save them, and that he still believed the past world was a better place... which isn't much better, but a little less of a spit-in-your-eye goodbye, I guess.