Take 10-15 minutes to research a Tegra X1, it's like saying "well I'm not sure about this gravity thing, you keep saying it but I'm not sure if I believe it". 

Thermal restrictions are a real thing, if they weren't we'd have an iPhone with PS4 level chips in it. 

You should also understand the size of the battery in say the Google Pixel C, which is required to run the Tegra X1 chip it has, see those two gray blocks:

That's the batteries (plural as in two of them). The battery alone is going to have to be 4-5x the size of the 3DS XL one. That doesn't even account for the space you need to cool the device. Likely the RAM Nintendo is using is going to have to be a higher bandwidth too (51GB/sec instead of 25GB LPDDR4) so that will also raise your heat and power draw, because games require a ton of memory bandwidth. 

And then you throw in things like detachable controllers .... well I mean those can't be the size of single Kit-Kat chocolate piece, they have to have some heft and width to them too. I'd say probably at least as wide as a Wiimote and at least half as thick for each side. There's just no plausible way this can be a pocket device just for practical reasons. 

Actually it's like saying what I just said, that I'm going with magic over logic. I know how it works, but even so, what logic dictates isn't acceptable, so I'd rather hope for the impossible. It's silly, but it's not like this some serious thing, I'll wait until we have actual information. Also, incase you think that I think hybrid, Tegra, detachable controllers, etc. are sure things, well, I don't, there's no proof so they are rumors. If NX is two devices, a home console and a handheld, then it'd still make sense for Nintendo to say Zelda BotW will look better on NX even though the handheld might not be as powerful as Wii U.

My guess is most people when they actually play the device will be happy with the larger screen size and overall size in general. This is going to be for the "big" Nintendo IP, not the little spin-off titles, it has to be able to run the next "real" Zelda and Metroid and Xenoblade games for example. You're going to want that 6+ inch display. 

There's no point in making a luxury car if you're going to gimp everything, if that's what you're making then make it right. 

I'd actually probably bet even when Nintendo makes a smaller version (several years later if possible), it won't be the better selling model. Just like more people choose the 3DS XL over the regular model. Once people get used to the bigger screen size it's hard for them to go back. Kids also love the larger screen size of tablet size devices. 

 Your post has absolutely no coherence at all with what I said, lol...

To steer things back on topic, a new mock up from optimiss on Neogaf:

Kickstand and swappable faceplates for the back. L/R buttons on both ends, kinda clever, so you have L/R buttons in detached mode. I could kinda see this working but I think it would be uncomfortable to use the lower d-pad and say the R shoulder on the other side. 

What I'd suggest is a "ZL" and "ZR" buttons under the L/R on the back. 

It breaks my heart that all of these mockups will probably end up looking way better than the actual device.

I honestly surprises me that you find this mockup good looking with those weird ABXY, the hard to use L&R buttons (how are you going to use them while holding the console) and the placement of the right analog stick.

Good looking and ergonomic is not the same thing. :P

They can't really help the placement of the right circle pad though, as that is part of the actual rumor and I assume you use the L&R buttons just like you usually would. The bottom ones would likely go unused in singleplayer mode and you'd just use the top ones (Wich don't look that diffrent from the 3DS ones).

The shoulder L & R buttons on the 3DS are on the top framework, not the bottom panel. They would be a pain to use in that position unless they are triggers, which they aren't.

Also, that mockup assumes that left and right detachable controllers will be symmetrical and used with the internal side pointing to the TV like a NES controller, henche the reason of the right analog being under the buttons. But that's based on an assumption, not from any actual rumor.

Emily Rogers, as well as the Lets Play Video Games Rumors place the right analog below the Buttons. As to the validity of those rumors, they might be doubtful, but they definitively exist.

You don't really see the sides of the device in this mockup. Recent rumors (on wich this mockup seems to be based) state that the device will be 15-16mm thick. That is plenty of space for L/R buttons.  I assumed that what we are seeing is the bottom part of the Button, rather than the side one. If you have a 3DS/XL turn it around and you will see what I mean.

If you're indeed supposed to press the part on the bottom panel, that would maybe be slightly uncomfortable, but far from impossibe. I agree that it's not a good solution though.