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.
You're not dead when you're petrified, either, which can lead to some pretty interesting exploits, rules-as-written.
Petrified creatures count as creatures, not objects, so rules-as-written you can determine if a statue is a petrified creature by trying to target it with a spell that requires a creature for a target.
With the cantrip Poison Spray, you can check for petrified creatures without using spell slots or risking damaging the creature, since it would be immune to poison while petrified.
If you want to go absolutely strict RAW with the creature/object distinction, resurrection spells don't technically work. They target "a creature that died", which, by an obnoxiously precise reading of the rules, can't exist. After they die, they're an object and not a valid target.
I don't understand why they can't just make "dead" a state a creature can be in.