Lets imagine for a moment that Splatoon, as a cartoony game with tons of potential based on gameplay mechanics and early impressions, managed to become the single most strategically intense game with the most wonderful feeling interface and even that its cutesy story somehow reach 'Bioware at their best' story telling...

Would it matter? I love my Wii-U, and the console is starting to get some respect, but would it matter to the masses if a cartoony game on a Nintendo console managed to be worthy of 'Game Of The Millenia' in terms of being enjoyable? Would the likes of IGN, Gamespot, or 'The Video Game Awards' ever give Game Of The Year ahead of the likes of Zelda or Uncharted or Halo?

I know that taste is subjective, but lets say that SOMEHOW the game managed to be bliss for anyone who played it. Would it matter in our current culture? Even to Nintendo gamers who already learned not to turn their nose up at 'cutesy' because of Wind-Waker? What about to the masses? - Are cuter games predestined to be niche? I mean, that can't be true, we have Minecraft.

(I am having a bit of a crisis in terms of my own design style lately. I may be transfering this to the cutest looking 'AAA' game I can see.)

You can't change mainstream perception or preconceptions. This has nothing to do with "the current culture". It is human nature.

Why do you think Anime is still regarded as a medium for kids and perverts?

It doesn't matter to the masses. If it's not perceived as cool, people won't play it. They would rather buy mediocre games that give them a better reputation.

The quality of the game does matter but it won't always result to high sales. Like, if Splatoon is a mediocre game, even less people will play it than the people that are thinking of playing it or on the fence about it. At the very least, it will get a cult audience which is better than no audience

What ifs. A bunch of what ifs.

OT, no, not to any big degree. But does that matter? No, because this won't ever happen. In the end, nothing really matters, does it. This isn't just for Nintendo games though. There are plenty of cartoony games that get discarded because they are for kids. Stop making it sound like the whole world is against Nintendo, I've seen people imply that far too many times.

It does still matter.

Most games that do well like COD etc are also well reviewed, they're just not that creative.

Games which people love tend to benefit from word of mouth and succeed in that way. What we can't change is things like timing, platform userbase and peoples taste. The latter is hugely important, even if the next battlefield gets a 10, I'm simply not a fan of military shooters... I'm not gonna buy it lol. In reality the games I love like Okami don't have a style that the masses are willing to indulge in more often then not

Actually my experience is Nintendo fans using it to point out why we're superior rather than the world being against Nintendo. - A concept I made a point to deflate in my first post. 

Also holy shit you've got some Wind-Waker ending levels of nihilism in your post. Call me egotistical but I'm gonna argue it does matter because I am a designer and my education has been entirely dedicated to specializing me in video games who comes up with ideas that wouldn't be too far from Splatoon in style. Thus if a potentially mind blowing experience does get passed over (assuming it proves mind blowing) by the masses, especially one that seem like the type of ideas I come up with, you can beat my sweet ass it matters. - Pardon the coloqualism.

Yea, Puppeteer and Tearaway suffered the same fate. But no, the whole world is out to get Nintendo.

All I know is that a lot of people want to buy games on their preferred consoles, once they have that console, they would start looking at the games they want regardless whether it's a good game or not. If that "quality game" is on a console that you could careless about it, it would pass as another game on the library on that particular console.

(assuming it proves mind blowing)

There's the "what if" again. Now, forgive my doubt, but I doubt you will make something so mindblowingly good that everyone would enjoy it if they tried, I also doubt Splatoon will be that amazing. I doubt any game ever will be that amazing.

My point was, this scenario doesn't matter because it'll never happen.

...but would it matter to the masses if a cartoony game on a Nintendo console....

There it is, "On a Nintendo Console". But this problem occurs on every console.

As I stated in my first post, cartoonish games, with a few exceptions such as Mario, and LBP, and Minecraft as you said (not carttonish, but very much 'cutesy') don't go mainstream. However, that migth be because there are very few AAA cartoonish games. Nearly all cartoonish/cutesy games are indie games, not AAA, and indie games rarely go mainstream, they might get a cult following, but will almost never sell in the millions (again, there are exceptions).

If you're developing an indie game, you should try to get a deal with one of the big three (it is possible!). I don't know about MS and Nintendo, but Sony has this pub fund where they'll pay you a certain price, in exchange for exclusivity or timed exclusivity. They'll also help you to make it easier with various fees and stuff.

Finally, one more time, Splatoon will never go mainstream, regardless of how good it is. The same can be said about plenty of other games. If that's all you wanted to here, there's your answer.