Because Americans are less insular about console buying habits.  They're happy to buy a console from a Japanese company if it's what they want.

Japanese are not.  Japanese people - for the most part - want consoles from Japanese companies.  And games from Japanese companies (although they're getting slightly less insular about that).

The Wii U is doing worse everywhere than the Wii. What does that tell you? Nothing.

In Japan, the 60GB premium PS3 had an open price, which stores set themselves. Many were selling for huge markups due to shortages.

Once again, you don't seem to get that the PS4 isn't selling because it has no games with little on the way besides MGSV.

If Sony wanted to do well in Japan, they should have released better launch titles. If "anime games" (your words, not mine) do the best (and yes, they do quite well), maybe Sony should have had two or three ready as launch titles? They do develop "anime games", btw, look at Freedom Wars and Gravity Rush on Vita.

The console industry is dying in Japan because Sony royally screwed up the launch. The PS3 did just fine, the PS4 is not. What sells a console is games, and the PS4 has none.

It's like the Vita situation in the west. Little to no support from Sony and few AAA games on the way means people don't care about it. Same situation but with the PS4 in Japan.

I know that. I was just showing that there is no compelling reason to buy multiplatforms on PS4 over XOne and thus there's no point in disregarding the japanese games that are or will be launched on XOne, even if they are not exclusives. All of this because Mystro-Sama claimed there were only western games on XOne, and clearly he's wrong.

PS4 will likely get most "definitive version" of console multiplatforms games this generation, it's a compelling reason. 

The WiiU is doing worse than the Wii in Japan because of the very same reason that makes PS4 do worse than PS3. And that will also make the XOne to do worse than the X360, mark my words. That reason is obviously the constant decline of the japanese market, which will make the 8th gen account for less sales than the 7th gen, just like the 7th gen accounted for less than the 6th gen. Anyone can see this. I wonder why can't you...

PS4 does have games and some are japanese like Yakuza, Ground Zeroes, A Realm Reborn and Dynasty Warriors 8. You're totally out of touch.

The launch window is not the only period to sell. Relax man, PS4 is still in time to sell a lot in Japan and even become first. Maybe Sony doesn't see it as a priority anymore due to its declining on the one hand and the emerging markets on the other hand. But that doesn't mean they will never focus any attention there anymore.

As for the Vita, the low sales of LittleBigPlanet, WipEout 2048 and many others didn't encourage Sony that much to continue heavily investing on their handheld. PS4 is the priority. Vita will just survive with the japanese 3rd party support. PS4 in Japan is definitely not on the same boat as Sony and the other devs are just starting there.

Even PC is downgraded in order to comply with console parity, let alone one console (PS4) over the other (XOne)...

If you think PS4 is anywhere near a priority for Sony in Japan, power to you. It's just as much of a priority for them as the Vita is in the west.

Out of all the titles you've listed, Yakuza is the only decent one. Real Reborn is good, but it is also available on PS3 and it is a sub-based game. Ground Zeroes is essentially a demo.

There are no first-party titles from Sony, that's the worrying thing.

Downgraded, console parity... Sounds like speculation to me. Go take a look at some facts, at some Digital Foundry face-offs: PS4 version comes ahead more often than the Xbox One version.

PS4 in Japan is not that much of a priority right now but it will have some attention in the future, that's for sure. PS4 and Vita will just improve in sales and games in the years to come. That's the natural trend in Japan.

I have only mentioned those 4 games as examples, there are more. And considering western games, there are many more. PS4 not having games is simply not true.

SCE Japan has actually produced Knack, so I don't know where you're coming from. They are also helping Capcom making Deep Down and From Software making BloodBorne. Not to mention The Last Guardian, which may come too. Is this little work done? Yes it is, I totally agree with you. But we can perceive that everywhere in Sony Wordwide Studios, not just Japan.

Digital Foundry face-offs... sounds like speculation to me ;) If you want me to look at facts, why don't you provide them?

Nevermind, went after them and found this:

http://www.eurogamer.net/articles/digitalfoundry-2014-watch-dogs-face-off

Both look like the same to me. I don't believe anyone will take some imperceptible graphic differences as the deciding factor to buy a next-gen console.