So you refuse to play 3.x then I take it?
I think you mean 3.5 (and 3.5 RAW at that).
3.X implies any variation and 3.0 Disintegrate was SoD.
I can't speak for JRRNeiklot, but while I prefer the SoD version, the extreme high damage variant also works well enough for me because (A) it almost never comes out different then SoD and (B) in the extreme cases that it does, you can still describe a narrative out in which the character takes terrible damage but isn't slain outright.
Again, I prefer SoD outright and (B) has never actually happened at my table. But the point is that there is no narrative absolute regarding the spell disintegrate and there has always been precedent within the game for saving and taking some damage but not being destroyed.
There are cases for which SSSoD is perfectly valid (poisons, for example)
There are cases in which partial effects are perfectly valid (Disintegrate)
There are case in which the effect is instant and all or nothing (Medusa)
In every case the narrative merits of the item in question drive what is right and what is wrong. It is when you start putting mechanics AHEAD of narrative that you lose the beauty of what RPGs can be.