I'd be severely disappointed, definitely. It would be like Duke Nukem Forever all over again, where it was said to be this definitive game, but ended up practically putting a dev company into debt with endless delays, to make it 'teh best game evar,' and yet still massively sucked.
If this game sucks, I have a feeling it might end up being the iceberg that sinks the Titanic. The ship doesn't sink right away, it still floats for a little bit, but ultimately the wound is still fatal. The reason I say this, is that the Wii U ended up being a flop due to not having enough decent games or matching other consoles' abilities, along with SS not being exactly that great. With BOTW generating massive hype and expectations, but then sucking, this might be a potentially mortal blow because of these things. People won't want to try anything with Nintendo anymore, because BOTW would end up destroying whatever good faith people have in their next games.