I have to say I'm with Guild on this one.
That Nintendo is optimizing the game for the system means nothing, zero, nil. It's a hard fact that the Wii U isn't a powerhouse of a console, which I'm very fine with. The games I've played thus far (Mario Kart 8, Smash Bros., Pikmin 3) have been amazing, just short of breathtaking experiences. However...
...we are talking about the next flagship game from Nintendo, so they have to compromise on something to deliver the promise of a huge open world. They can't keep high quality textures all around with high polygon counts and a big draw distance. It's technically impossible. To follow your example, GTA V on PS3 looks like JPEG compressed vomit. GTA V on PS4 is far better. The only kinds of games where raw performance and processing power is required are open world games. You just can't create a game with the graphical level of e.g. The Last of Us on PS4, have a huge draw distance, lots of polygons, and high quality textures on a Wii U. You can't. It doesn't matter who is making the game, even Nintendo can't pull that off. My evidence to support this claim? For one, they went with cartoonish graphics again and not realistic graphics. It doesn't matter how Nintendo washes down this by saying it fits the "art style" or whatever bullcrap. It's by function and that is to ensure the Wii U won't explode while loading up the game. And secondly, what we've seen is pretty much a dead town. Who cares about a huge open world if there's nothing to do?
Optimization, in many cases, is actually much more important than anything else. The PS3 version of many ports was by far the worst (even though the Xbox 360 had much less computing power overall) because games were not optimized for it. Games that were optimized for the PS3 (like The Last of Us) looked absolutely incredible on the hardware.
The ability to make a visually stunning game is not engendered by the speed of math. It is created by the artistry of the programmers, the level designers, and the artists. The number-crunching is just the canvas.
Also, your "evidence" shows a complete lack of understanding of the mathematics behind game development. "Realistic" graphics often require less computation than "cartoony" graphics. For instance, cell-shading is a common technique used to emulate a hand-drawn appearance that requires quite a bit of extra processing power.
Also, your claim that Nintendo did not choose to use a more realistic art style because of lack of processing power is not supported by the evidence. Nintendo rarely chooses this sort of style for its games for primarily artistic reasons and when it does choose a more realistic artstyle, it manages to make it look pretty good (for instance Other M and Fatal Frame 4 for the Wii).
In any case, games like Skyrim ran fine on last generation consoles with their massive worlds and "realistic" artstyle, so there is no question that a game like Zelda for the Wii U, which has access to a faster GPU, more (and faster) RAM, and a myriad of optimizations for the platform that Skyrim lacked, could run just fine and look great on the Wii U in any artstyle that Nintendo chooses.
At the end of the day, games are about the painting, not the canvas. If you care about canvases so much, buy a 4K TV, a $5000 GPU set, and pretend like the hackneyed mutliport AAA titles you are playing are somehow better than games like Zelda because they have better draw distances.
The first open world game was Ultima ya dingus. The first Zelda is roughly open world, you'd look more towards Wasteland or other Ultima game as early open world examples.
Nintendo certainly didn't "invent" the genre. Even then, Nintendo may have brought forth many innovations 30 years ago but it means jack shit today. Just because they made a great game 30 years ago doesn't mean they'll make one today. That's pretty damn evident if you've played some of the half-assed crap they put out in recent years.
I'm not sure how my statement that, " Nintendo actually invented the open-world game on
home consoles with the release of
The Legend of Zelda in the 1980's, which was
one of the first open-world graphical games ever," is contradicted by the fact that Ultima came before it.
What I do know is that you might want to devote more time to understanding what your read and less time to criticizing others.