Yep Switch is selling more monthly than the PS4 there atm.

However its still around 2m NSW to 5.5m+ PS4's.

Its hard to say its getting its "ass kicked in" when its 2-3 times the total consoles of the switch there.

Why did you inflate ps4 and deflate switch when they are both around 400,000 past the their respective million number 2 and 5.

You've lost the argument in the first three words of your paragraph, impressive I must say.

OT : It's the second best selling country, yea, but as a region it's getting smaller and smaller.

http://www.vgchartz.com/article/270349/ps4-vs-ps3-in-japanvgchartz-gap-chartsseptember-2017-update/

It’s tracking exactly like PS3 in Japan

Actually Switch is at 2.4m while PS4 is at 5.6m, its matter of weeks when Switch will have half of install base of PS4 for less than 10 months on market.

I think that’s strong wording, considering the state of gaming there. It goes without saying that a device that has all the console features a casual gamer could want, but portable, would sell much better in a market that has been heavily driven by mobile gaming for the last decade, than a dedicated home console. It doesn’t make much sense to compare the two, as they really aren’t competing seeing as they’re aimed at different demographics and all. I still say PS4 is doing great, and if it can outsell PS3 in Japan, then it’ll still be a pretty big success, regardless of how many more units Switch sells. 

It doesn't mean the market is irrelevant like some are trying to claim, the main bulk of Japanese developed games don't do that well outside of the country especially in Europe, that 1/4 in Japan still pulls in far more for them than the rest of the world combined. This is why many games right now are being announced as PS4 and Switch with no X1 version, some people are trying to push a notion that Sony would be alright with out Japan when all that would do is surrender almost all third party support in the country to a competing platform.

I see a lot of comments from aggressive Nintendo fans trying to bash the PS4. They seem way too eager to forget that Wii U was a thing, and was actually a direct competitor to the PS4 there, as both are dedicated home consoles and were competing for that demographic. Don’t suddenly pretend that that fight didn’t go well in PS4’s favor. Let’s be honest; if Switch didn’t have the heavy portability factor, and was a dedicated home console like PS4/ Wii U, it’s sales would be significantly different. You’re trying to compare apples to oranges. 

This is true even if you ignore the PS4 vs. Wii U aspect. Japan just by and large doesn't buy home consoles anymore.

Hell, the gaming market in Japan is currently more than 75% handhelds not including the Switch (29 million handhelds, 8.8 million home consoles) Look at that compared to the other countries the OP was talking about.

Japan:  76.7% handheld. 23.3% home console.

Germany: 38.6% handheld. 61.4% home console.

UK: 33.7% handheld. 66.3% home console.

France: 50% handheld. 50% home console.

US: 33.4% handheld. 66.6% home console.

Nobody else is even close in their preference for handhelds. in most other major markets handhelds account for about 1/3rd of the dedicated gaming market, not more than 3/4 of it. There are several reasons why Nintendo decided to make the Switch portable. One of them is absolutely the shift in the Japanese market.

If Sony is leaving the handheld market, why on earth would Japan still be as important to them? (that's a more general question, it's not directed specifically at you)

Well i never personally said that Japan is irrelevant for Sony, just that his numbers in the OP dont paint the whole picture.