You realise that PPI (pixel density) of 1080p on 24" is 92, while 720p on 6.2" is 237 PPI!? So 720p on 6.2" looks 2.5x times better than 1080p on 24".

so bring a backpack!!!!!

:/

Bring a backpack for one device? 

Where the fuck do people even put their 3DS?

I have my smartphone, keys, and wallet anytime I go anywhere, that means no 3DS is going in my pant pockets no matter what.

When I take my 3DS anywhere it's on a flight, and the 3DS is always thrown into my back pack.

I've never walked around with a 3DS in my pant pockets. Hell even back in the day, you couldn't really fit the OG Game Boy in pant pockets, the thing was the size of a brick, lol, but I'd just take it in my back pack or you could buy a small carry bag like anyone with a tablet or Kindle reader does.

People take paperback novels (remember books .... the original portable entertainment device?), tablets, and before you could ever fit one in your pocket, a Game Boy too for years with them, now suddenly a 6-inch tablet gaming device is impossible. First world problems. 

Only if the distance is the same. I tend to hold my handhelds and mobile devices a lot closer to the face than my PC monitor. But I agree, anything around 200 ppi on mobile devices is okay for me, 300 ppi and more is overkill.

I put it in the same pocket as my phone since my phone is slim.

And yea, people used to take those but that doesn't mean they wouldn't have prefered to take less if they had the choice. And now they do in which case they take less. It isn't up to the people to adapt to industries, it is up to the industries to adapt to people. 

Nintendo is adapting to how people use mobile devices ... the fact is that you're likely a very rare customer type ... not many people carry a 3DS or Vita in their pocket. I would bet Nintendo has done fairly extensive market testing on that too.

The smartphone has taken that place and it's never going to give it up, so Nintendo is adjusting to market realities by offering a different form factor device for the portable market that can do more than a 3DS could ever dream of and thus having the potential to be more competetive in the market place of today. 

Phones are getting larger too and more people prefer larger phones so that's not helping the traditional handheld devices. Most people also have their phone in a case (because a phone unlike a game system, is important to their day to day life and if were to be broken it causes a real inconvienance for people), so that takes up a lot more space. Factor in the trend towards skinnier jeans too and it's bye bye 3DS and Vita. 

By entering the tablet market which is not only pretty competitve but also has been in decline?

Tablets still sell like 20x more annually than what the 3DS/Vita have been putting out. 

When I got an airport, I see literally *hundreds* of kids using mobile devices, and the ratio to 3DS/Vita is ugly. Uggggggggggggly. 

Like there's maybe one kid I see with a 3DS/Vita to like 20-25 playing on either a tablet or their mom/dad's smartphone. 

And I fly a lot for work, through Canada, US, all through Europe, and even Japan. I'm in about 20 different airports every year. This isn't even a contest anymore. On the insulated confines of a hardcore gaming board, things seem a lot more cozy, but when you get into the real world you really see how badly smart devices have made gaming portables their bitch. 

I remember on one flight I was sitting across from two elementary school age sisters who both had their own tablets, and I pulled out my 3DS to play and the girl shot me a look like "what ... the ... HELL is that thing?", lol. I just chuckled. Nintendo has no choice but to pivot IMO or become completely irrelevant anywhere outside of Japan. Kids *love* their tablets. 

All that would happen if Nintendo made "4DS" would be that it would sell even less than the 3DS, probably considerably less. At least a form factor more ammenable to what kids like to use today might have a shot.