to be clear the only reason i call Zelda an Adventure game even if it's exceptionally close to being an RPG is because it said "Adventure" on the original boxes for the NES... back in the 80's NES days the boxes had the games categories printed on them, as well as with their descriptions in Nintendo Power also being labeled with a specific category... the Nintendo Power Strategy guides were also seperated by these categories... in all these instances it was categorized as Adventure, so i figure Miyamoto decided it was Adventure, and so i go with that...
this is as i recall it from the 80's, i was a teenager then so there's a chance i could be misremembering something...