The new look is waaaaay better.

"Fuck the market"?

Sure, if you're a loyalist you'll get the games you want in the short term, but fast forward a decade and Nintendo will likely be out of business.

Nintendo fans alone aren't enough to keep them afloat, they need to tap into markets they're not currently reaching to survive.

Well no, to survive they need to build their fanbase. They tapped into markets last gen, but failed to make 90% of the new comers into actual fans. The Wii period was a gilded age, the good sales figures hiding the decay of the Nintendo and Wii brand as Nintendo sat on their laurels for the better part of that gen in terms of marketing and in some periods in terms of software production.  And on that note, this art direction is far from hamstringing the possibility of that. 

You don't build your fanbase by appealing only to the ones you already have while doing nothing to attract new ones.

True, but art direction has little to do with that honestly.  People like to build up the "realistic zelda=sales, unrealistic=fail" shtick, but if that were true than Majora's Mask would be higher than Wind Waker in terms of sales instead of over a million behind on a platform with a much larger user base. 

This game is open world, the first trailer had a lot of action to it, and so long as they market those aspects (fluid combat, open world exploration, action, epicness, etc), the art direction will have little effect.  Look at No Man's Sky's hype.  Look at Borderlands.  Unrealistic art style isn't hurting them.  Market perception and reception are both more malliable than people make them out to be.

Actually the style of Borderlands has likely hurt its sales compared to what they could have been.

People base a lot of their judgements on first impressions, and graphics are that first impression.

Many people are repulsed by colourful, cartoonish games, especially in today's dudebro-ruled market.

You can't just assume without evidence that Borderlands has underperformed due to art direction; you would need proof.

Also, as I said, such perceptions are quite malleable. Many things that were once niche or "too geeky" are mainstream now. All thanks to good marketing schemes.

Same goes for you assuming it hasn't impacted its sales negatively.

It's Aonuma, cut him some slack.

Well if you're going to play that game, we may as well take the YouTube comments style and shout obscenities at each other for all the good it will do.  All that we know is that the games are multimillion sellers with the art direction they have; that is what I put forward and that is not an assumption, that is a fact.  And asking me to prove he nonexistence of potential buyers put off by one specific element of a game is silly. 

However, I would like to point out that Wind Waker sits at the 6th best selling Zelda game spot while Majora's Mask is at 11th.  And a bit above Wind Waker is Phantom Hourglass, a spinoff with that same style.  It's not all about art direction, there are other forces at play.  You can't just take the numbers in a vacuum.