Yes, there was no saving the Wii U. Part of why is that its software pipeline was broken right out of the gate and the droughts started immediately after launch. Software sells hardware, so if there's no new software for an extended period of time, the hardware won't sell. That's why Wii U sales were so bad so quickly. Conversely, there were bumps to hardware sales when new software got released.
Yes, Japan prefers handheld consoles because they are more convenient and the only advantage that a home console can provide nowadays are better graphics which hardly anyone cares about. Still, if home console or handheld console was the only thing that mattered, the Vita should have sold better than the PS4. Since that didn't happen, the logical conclusion is that games are more important than the console itself. But since you keep being in denial that games matter, we get posts from you where you claim that the software droughts of the Wii U did no harm to its sales.
It's pretty easy to explain why the Nintendo 64 as well as the Xbox One sold respectable numbers in the USA, but not elsewhere. The rate of multiconsole ownership is historically much, much higher in the USA than anywhere else in the world, so international struggles of a console don't translate to the US-American market in the same way. The costs of electronics as well as disposable income allows US-Americans to buy more consoles as well as games than people of other countries. Indeed, it's not only that the average gamer in the USA buys more consoles, but also more games per console. The USA leads the world in tie ratios by a comfortable margin. An additional reason for the relative success of the Nintendo 64 and the Xbox One in the USA is software that appeals to the market. The Nintendo 64 heavily dominated the FPS genre in its generation, the Xbox brand in general has the image of the American console because of its software library.
It would make more sense to say that Nintendo reacted to Sony's decision to only support one console going forward. Sony announced in mid-2013 that all of their American and European studios were going to make PS4 games, so Sony's exit from the handheld market was already a done deal at that point. If Nintendo hadn't combined their home console and handheld efforts, they would have been the only console manufacturer to support two separate consoles simultaneously which is an obvious competitive disadvantage.
You do realize sometimes software, cannot sale hardware, dreamcast, Xboxone in europe and wiiu are proof of that. like you that was part of the problem, only part of the problem, even you admit that at least were getting some where.
again nobody said being a handheld is the only that mattered, but it will sell significantly more then a stationary home console givin the same software a portable will probably sell double what a home console would. PS4 has sold 10 times the software vita has in japan.
Your explanation doesn't explain why playstation consoles sell much better in Europe the USA, so it's void. Europe and USA, really have similar preferences when it comes to games, except that fifa is much bigger in Europe.
Very bad examples:
Dreamcast: Sega couldn't produce fast enough and cheap enough, and were banking on the software sales to make money. That didn't work out, and Sega had to pull the plug to survive, as the better the Dreamcast sold, the more money Sega lost. Had Sega not been in such a dire position financially, the Dreamcast would have sold better than the Gamecube and OG Xbox.
XBO in Europe: Europe was for a long time a region of PC players, and many still do in parallel to a Sony or Nintendo console. This makes an Xbox however very redundant, since it's games also come out on PC, which most people have.
Wii U: Wii U software couldn't sell hardware because it didn't have software to sell the hardware. Rol asked for the games released in January and February after launch, I checked: a whole 4 games in the US, and even just 3 in Japan - and only one of them not being an Indie title. Without games, there's no reason to buy a console.
As for why Playstation sells better in Europe, it's because they took over Segas players from that region plus all the new ones in the 1998-2004 period of rapid growth since all it's competitors fizzled out for one reason or another, meaning Playstation was their entrance into console gaming. Which meant that by the start of the 7th Gen, Sony had the European console market cornered and by the balls - and then lost their quasi-monopoly with a disastrous launch. But since they owned so much of the market, the loss still wasn't strong enough to kick them from the throne.