It kinda blew my head when I realized there's not a topic dedicated to the upcoming Nintendo platform arround here, so I thought it totally deserved one.
Because Nintendo haven't been relevant since about a year after the Wii was released.
My top tips for Nintendo:
1. Stop fannying about with fancy hardware peripherals and make a solid console that can compete with your contemporaries. No one wants an underpowered console, regardless of the gimmicky controllers you come up with.
2. Allow third-party developers to make games for you.
3. Come up with some new games and stop rehashing the same IPs year in, year out.
That's really all it takes for Nintendo to get back in the ring, but they seem to be content to just make a load of crappy hardware that is fun for ten minutes. I've had a Wii for 6 years, I've only ever played it twice. The last two times I moved house, I haven't even bothered to unpack it. I'm not even sure where in the house it is.
That, right there, says everything about Nintendo.
Just because the Wii and Wii U didn't quite equate to the success of the PS3/4 and 360/One doesn't at all mean they aren't relevant anymore, it just means they tried a different path than them two, thus catering to a different crowd to the 'typical' gamer these days. As much as I love Nintendo, they shoot themselves in the foot so many times that they should expect failures, but it's time to work on all that. For example, if I wanted to play online with my friends, the PS3/360 was a simple case of adding a username and voila, job's done...The Wii, if I recall correctly, had some type of code that you had to input and some other sh*t like that. The Wii U fixed this in some ways, and even extended on it by adding types of 'pages' for each game, like Facebook pages, where people could leave comments and start topics etc. By this time I knew none who owned a Wii U so wasn't able to test out how the friends system worked. Another way they shot themselves in the foot was by making certain games not compatable with the Gamecube controller, thus turning a lot of people away from playing certain games. As much as I love Zelda, I have never played Skyward Sword purely because it's motion controller only, and the same goes for Mario Galaxy. Microsoft and Sony offered motion control peripherals too, but were only neccessary for specifically tailored games.
On to your points:
1] All 3 companies at the time worked on the same overall 'motion control' aspect, but Nintendo were the only ones that tried too hard to force it upon everyone, whereas Sony and Microsoft released it as some type of add-on, realising it was just a gimmick. Had Nintendo gone the same way, people wouldn't be bashing it as much at all, but as I said above, making your exclusive titles only playable with the gimmick was a disaster. The Wii U did brilliantly though, and I don't get how anyone can bash the tablet controller at all...2 screens at the same time with touch functionality, yet offering a controller that worked on all titles...the tablet also allowed you to play the game purely on the tablet and have the TV turned to something else, and in a day and age where mobile gaming is huge, this was a fantastic idea.
People don't realise that it's not the gimmicks that kill a console, but how the company works with them.
2] Third-party companies were still releasing games on the Wii/U, but people were already turned off by the console for people to even care. Again, it's all about what the third-party companies bring to the table, or what they don't. Roll back a few years and you'll see that Rare dominated the market with their games for the N64, yet Microsoft bought out Rare and made them work only on the Kinect, this ultimately ending the company, hence the company have rebranded and are working on proper titles again.
Point been, just because you have a third-party work for you doesn't automatically equal success. Had Rare been allowed to continue making games for Xbox, it would have been huge. Conker, Banjo, Goldeneye, Perfect Dark etc...
3] I disagree and agree with this point. Keeping an exclusive IP isn't bad at all, it's just how you go about it. Mario is still a huge success, but just not to the extent of what we saw on the N64. Mario Galaxy worked on the gimmick, and then all we saw was new entries in the Kart series, along with side-scrolling games, whereas most people, me included, are still wanting a proper 'SM64' type sequel. Zelda, another series that relied on their gimmick on the Wii, then kept itself alive by means of HD releases, whereas the only real other entry on a home console was Hyrule Warriors, some type of Dynasty Warriors rip-off sh*t that I never bought due to the realisation it would quickly become repetitive and boring, and seemed to rely heavily on selling on the Zelda title alone.
Breath Of The Wild is looking great, but yet again getting bashed on the style used, and the fact that no real bosses or dungeons have been revealed, only the open world.
Nintendo are just stubborn and seem to want to stay away from mainstream as best as possible, which isn't a bad thing at all, but it's all about what they bring to the table.