Why does emet selch consider us not to be alive?

[Cleretic]

The answer is that he's racist. (or whatever '-ist' you want to describe this as, I've seen a decent case for ableist.) I know that's a really blunt and brutal description, and might feel a little mean to people who like the character, but it's really just where we have to start here: he is making this argument out of prejudice and feelings, not out of facts and logic, and we shouldn't look for the latter in it because it's just not there.

The Ascians' view of 'I don't consider you truly alive' largely comes from them starting at the conclusion of being superior and then backfilled their justification; there isn't logic to it, or at least not logic that would hold up or be in any way agreeable or sympathetic. Yes, the dragons fly in the face of this statement; no, that doesn't put any more logical holes in his statement than there already was, because it already wasn't a statement made with logical grounding.

Some argue that when Emet's saying this, he doesn't really believe it and is mostly just convincing himself. I've never seen clear proof of this, nor do I necessarily think that makes it better (might actually make it worse, in fact, because now it's just him knowingly dehumanizing and justifying the murder of humans)... but also most of the Ascians seemed to be on the same page on this, so it's not exactly dismissable just because Emet might be lying.

[Kakurady]

Some argue that when Emet's saying this, he doesn't really believe it and is mostly just convincing himself. I've never seen clear proof of this, nor do I necessarily think that makes it better (might actually make it worse, in fact, because now it's just him knowingly dehumanizing and justifying the murder of humans)... but also most of the Ascians seemed to be on the same page on this, so it's not exactly dismissable just because Emet might be lying.

Ascians deceive. And Emet-Selch deceives even himself, for he is Tempered*, and has no choice but to carry out Zodiark's plan to revive the ancients. This requires him to cause widespread death and destruction, contrary to his skills as a builder of civilizations. Dehumanizing mankind is how he can cope with the cognitive dissonance, because for Emet-Selch, even bringing back his brethren cannot justify murder of mankind.

* At least, considers himself to be Tempered. There's some argument on whether Ascians are in thrall of Zodiark, and I believe they are.

[Cleretic]

Ascians deceive. And Emet-Selch deceives even himself, for he is Tempered*, and has no choice but to carry out Zodiark's plan to revive the ancients. This requires him to cause widespread death and destruction, contrary to his skills as a builder of civilizations. Dehumanizing mankind is how he can cope with the cognitive dissonance, because for Emet-Selch, even bringing back his brethren cannot justify murder of mankind.

* At least, considers himself to be Tempered. There's some argument on whether Ascians are in thrall of Zodiark, and I believe they are.

Yeah, that's also not really better, is it? It adds more factors, but not really in a way that absolves anything, or gives the line any greater weight in any particular direction; it's still post-hoc justification for why he's okay with what he's doing, which is absent of any actual facts, evidence or logic.

For what it's worth here, the way I read the Ascians being tempered is that yeah, they are--there's a line in 5.3 that describes the process of it--but that it's not really a 'full' tempering like we saw from people tempered by Ifrit and Lakshmi. I don't know where the OP actually is in the story (the characters listed in their profile top out in the 50s and don't even have jobs, so that's clearly not usable to figure it out), so I'll spoiler-tag the explanation so I can freely pull in later evidence.

Clearly Emet's of sound mind, and mentally is actually not particularly different than he was when we met him in Elpis (neither is Lahabrea; Elidibus and Fandaniel are but those are whole different situations). Instead, I think the Ascians are tempered in the way described by Tiamat in 5.5: it's a constant voice in their head, but one they externalize and can even dismiss to some degree. Consider Mitron in the Eden storyline, clearly off doing his own thing, and especially Fandaniel, who seems to go completely against what his tempering would probably be directing him to do. So while their tempering is pretty much an undisputed fact as far as in-universe information, it's clearly not strong enough to override any other desires, plans or priorities they might have.

Perhaps you could argue that's an element of Zodiark being a primal of darkness; a major part of the tempering process as we learned about it in 5.4 was an aspecting towards light removing the sense of self, so Zodiark as a primal of darkness... well, maybe just wasn't nearly as good at that part. But regardless of the 'why', I think the end result is pretty clear: Zodiark did temper them, but to such a light degree that it's easily rebelled against, as neither Mitron nor Fandaniel express much difficulty in doing so. Which, if that's true, casts a bit of a shadow on Emet using it as an excuse; given that those two can shirk the influence of tempering when it doesn't suit them, then perhaps Emet never actually disagreed with it.