Disclaimer: this is purposefully obtuse.
Other effects in the game which explicitly state they kill you:
Shadows, succubi, massive damage, death saving throws, beholder death ray (notably not even their disintegration ray kills you), power word kill, vampires, mind flayers, night hags, drow inquisitors.
Clearly, if they intended for disintegration to kill you, they’d have said so. Since specific overrides general, and there is no general rule that disintegrated creatures are dead, I rest my case. QED.
I think the bigger problem here is that you’re arguing in bad-faith.
Bad faith? The only faith I have is in the rules as they are written, like a gospel!
That’s why when she gave you four arguments that should clear the matter up, you cherry-picked one of them and said that it was “making an assumption” and therefore invalid, even though the “assumption” was that the player understood language. That’s why you ignored the other three arguments entirely.
You’re deliberately trolling for attention. and this faux-innocence isn’t fooling anyone.
I haven’t ignored anything intentionally, if I haven’t addressed a supposed claim to why this isn’t RAW it’s because it was added in an edit after I replied.
(psssst, read the first line of the OP)
The first line of the OP does tacitly say that you’re arguing in bad-faith, yes.
Tough crowd!