There's so many reasons why. To start off with, what people tend to miss is the Wii U's been out a year longer. Always keep that in mind. I've seen a lot of people use the claim that the Wii U has a better library and the XB1/PS4's sucks, which you could argue is true but I'd bloody expect it to when it's had a year longer to do it! Compare the Wii U of today with the XB1/PS4 of today in a year's time and that's a fair comparison but one rarely people make. I don't think Nintendo fans want to make fair comparisons these days though.
Also let me just begin with saying that
I like the Wii U! I like Nintendo! But liking them doesn't stop the fact that their are problems, clearly, and the act of discussing them is not some attack on Nintendo like people automatically assume. Every negative thread about the Wii U always gets annoying people who just defend them, thinking everyone's just a hater for simply discussing it, whereas everyone who contributes to an Xbox/Microsoft hate thread are all bang-on correct and justified! Blind haters are as stupid as blind supporters, but the act of discussing a console with problems does not inherently make you 'a hater'.
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To get into it, why is the Wii U failing? I think Nintendo just completely mis-read the market and released a less-than-desirable product, it's not the next 'cool' thing kids want, and with a schizophrenic target audience which just ended up alienating some gamers (those who thought the Wii was 'kiddy' and not for them aren't likely to change that opinion with a console called 'Wii U', though Nintendo claimed they wanted to capture that type of player) and not attracting the ones they hoped for (casual market which made the Wii soar).
The name was also a mistake, when they had hoped for other results it just made consumers confused, and it didn't help that they barely showed off the actual console itself. The PS4 is a great name, simple and plain, and the Xbox One took its beating for the name but it's clearly a different product to the Xbox 360, no problems there. The Wii U didn't have that same luxury, and it's pretty well-known a common misconception was the Wii U was just a peripheral for the Wii. A horrible first-year line-up of games also didn't help; I know people will point out a few good ones, but, where the hell was the A-Team? Games that are coming out in the near future, games that people claim will 'save' the Wii U, are games that should have been out as close to the launch window as possible so it didn't need saving and just sold well to begin with! It would have given them some strong-selling titles to market, and that leads to the next-point which is marketing. In contrast to the frankly brilliant Wii advertising, the Wii U got barely anything. I'm not sure what it's like in other countries, though considering I've heard many people agree with this I'm going to assume it was bad too, but I'm not exaggerating when I say Wii U advertising in the UK was almost non-existent. Like Sony and Microsoft do, try and get their adverts in prime-time spots (I saw an Xbox One advert while watching Top Gear, which is a big show), Nintendo didn't seem to bother/care at all. And the UK responded in kind. I mean, Microsoft is making more effort in Japan for the Xbox One than Ninty did with the Wii U in the UK!
Finally, I think it just dropped off people's radars now. When a new product doesn't make a splash and just slowly fizzles away in the eyes of the public, usually that's it. You either need a new marketing push or a new product, which would ensure a brand new marketing push, but, it's not like the general person sits on IGN and looks at Wii U news and patch notes and new features. If they didn't like it at the start, they won't actively seek out if it has gotten better. That's Nintendo's job, to
tell them it's better and to
tell them that they want it! Which leads back to why I think Nintendo dropped the ball with the marketing and they need to do an almost re-brand of the console to liven it up. Otherwise I doubt they'll ever really capture anymore gamers than the core Nintendo crowd, and unfortunately that isn't a crowd with size enough to keep a console happily afloat.
And now? When I walk into my local GAME, there's a wall dedicated to the PS4 and a wall dedicated to the Xbox One, with tonnes of games there. And the Wii U? It shares a shelf with the Wii, 2 boxes for the Wii U and 1 box for a Wii, and all of their games are just together. Not even separated, literally, the Wii U games take up 1 and a half shelf and then the Wii games take up the rest, which is about 3 more shelves. I mean, consumer confusion was a problem and that can't exactly be helping the situation. Even the Ouya and Gamestick have their own shelves! Even the Microsoft Surface and other tablets do! A next-gen console not having it's own big area in the biggest dedicated game store in the country is really when you know you've hit some bumpy roads!
I know people will valiantly leap to Nintendo's aid, but, I'm not bashing the Wii U. I like it as a console. It's not trying to be some cut-down Gaming PC, it's just a simple and efficient gaming machine, albeit with some ridiculous and short-sighted design choices (MS and Sony had digital games tied to accounts last-gen, Ninty!!!!) and I do quite like it. And I can respect a company at least trying to innovate, though I don't feel the Gamepad is as exciting an innovation as Nintendo has had before. It's the same reason why I like the Xbox One, I want more than just better graphics with a new console generation, and at least the Gamepad and Kinect try to do that. Whether they succeed or fail is an opinion, but, I'd rather all companies try and fail to innovate than never get anything new.
I also don't feel the people who desperately try and defend Nintendo are helping the situation. If a company does something bad, it's not a betrayal or anything to say so. I love Nintendo but the Wii U, while okay, is not at all what I imagined it could have been. I feel it's lackluster. And I'll say that and I don't need some fanboys raging because they have a different opinion about it. I mean, I love Valve, they're my favourite gaming company, but when they do something stupid I go on the forums and I post my opinion on it. No matter how much I'm bias to them, surely you want a favourite company to flourish? Some people may be perfectly alright with some of Nintendo's decisions and genuinely not care, sure, but I feel at times it's just white-knighting and is the stupidest thing you can do for a company you like.
To reply to some a point from the OP:
Ghost said:
I think that people care too much about how a game looks rather than how a game plays. I really think that is the bottom line.
I definitely disagree with that. People do care about how a game looks as well as it plays, yes, that is a fact, however much people try and furiously down-play a game's looks in the overall scheme of things, but if they cared about it too much then why is Call of Duty selling? Not every single game on every single platform looks the same, there's better looking ones and worse looking ones. If people cared too much about graphics then why would they be buying Call of Duty games on their consoles when Battlefield looks an entire generation ahead of it almost? Because they don't care about it
too much. They care about it a normal amount, and at the end of the day they like COD's gameplay and so buy it.
People tend to care more about art-style than raw graphics. Nintendo could release games that look miles better than anything else on the other consoles, but their games are colourful and bright. Look at 3D World. If your not a fan of that type of art-style, then you wouldn't like the game, however graphically superior it is to other games.
Also, your mistaking more power in a console simply giving graphics. This is just not true, more power gives you more everything. The size of a world, the spread and intensity of content, the complexity of AI and how much there is, dialogue, every single bit of sound executed, and emergent branches in gameplay. All these things, everything, requires more power. When you play a game there's millions upon millions of processes going on in the background. So people like more powerful hardware because it has more potential. I mean, look at Skyrim. It was a massive world but it was dumbed down in other aspects not because "lol bethesda sux" or anything, it's because a world of that size with all that content is one hell of a strain on the console, and so they couldn't make stuff better. People think you can slot in more advanced AI or more sophisticated random events but that required processing power that, evident from the problems it had on PS3, just was not an option.
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tl;dr
Nintendo's problem was just trying to make the Wii U do everything, hit 2 markets of which neither cared anymore/still, and attempting to clip the other consoles to the post by releasing early and almost squandering their year lead with a lack of games and a greater lack of marketing.
I'm enjoying my Wii U, it's good, but I don't really see it ever kicking off anymore. Nintendo might save it, but I think anyone expecting more than a third-place finish is being very optimistic right now.