The last 4 Mario games of this generation (New SMB, 3D world, 3D land, Mario Maker) have all been amazing, unique titles.
Zelda is a little bit harder, because the IP is a bit more restrictive. I honestly haven't played one since Twilight Princess (which I thought was great). The upcoming Breath of the Wild looks incredible though.
I hope they never stop making Mario and Zelda games, as long as they stay consistent with their innovation and creativity. To me, saying that they should stop, is like suggesting that they should stop making Bond movies.
Super Mario 3D Land/World feel manufactured to me. They have good ideas but it's just a bare series of levels. Barely any secrets. Nothing new other than the cat suit. Just feels like a dumbed-down version of 64/Sunshine/Galaxy with a SMB3 world map.
Mario Maker is a simpler version of Lunar Magic, and far less powerful; but far easier to use. Unique? No.
I've been playing Mario forever, and the games are consistently polished, but they need new ideas, not just rehashes of older ones. They're getting old.
I'm not so sure. My nieces and nephews all under 13 don't talk about nintendo, the way kids in the 90's did.
They talk about call of duty, minecraft,playstation 4 and various ios android games. I asked them if they wanted me to buy them a wii u, and they said no. They wanted a steam gift card instead.
Personally I think Nintendo is losing relevance with the new generation.
I wonder if anybody under 25 has any idea who half the characters in Super Smash Bros are?