Why the desire for low magic?

[Batcathat]

If you tried to classify… darn senility… "War. War never changes. … Life in the vault is about to change." … that series as an RPG, at least I could see that it gives you choices of approaches at times… which at least comes closer to approximating role-playing, if you happen to be playing a character who exactly matches their limited selection of rails.

You're thinking about Fallout.

So… what did I miss?

I don't think you're missing anything, as much as having a different definition of "role-playing game" from those who label Diablo as such. I think the idea is that you are playing a role in that every Diablo character is (theoretically) different depending on the choices of the player. While I don't necessarily agree with the definition, it's probably too established to change much (though it feels like descriptions like "action game with role-playing elements" or whatever is getting more common).