The reason why zelda is the most talked about game at e3 is because its the best game at e3. All the other games were CG movies for people who like to watch CG movies. Nintendo dropped one bomb and it blew up big.
Let say nintendo dropped one game like "Horizon". Its a cool game yes, but what's there to talk about? You run around and kill robots for a week and then you put it down for the next big AAA game. As soon as the game launch its forgotten. If you want Horizon you got it. I am surprised that nintendo can come to e3 with one game and still create buzz.