Yeah, they can only add free content if the game is unfinished, not because that's Nintendo.
200cc means Mario Kart 8 was unfinished until this year.
If we didn't have these updates, there may have been complaints about a lack of maps, but nobody would say it's unfinished. Before the Direct, we thought we knew everything about the game and most people were happy with the content, but then the Direct said "Hey, we're adding more content for free", so now it's "unfinished". This whole argument is utterly ridiculous.