What is the alternative to SD Cards for a handheld platform? Expensive as fuck properitary memory (see: PS Vita)? Please. 

Is this what you want? 

https://www.amazon.com/32GB-PlayStation-Vita-Memory-Card/dp/B006JKASCK

$90 for a 32GB memory card that gives marginal gains in quality and speed, if at all? 

SD cards have been perfectly fine for 3DS owners who have gone fully digital. I doubt anybody who buys a cheap Chinese knockoff SD card cares about transfer and read times, because otherwise they'd not buy the cheap chinese knockoff. 

I still don't understand how Nintendo compresses their games so well. I have some theories but their file sizes are always beyond small, other developers struggle to compress the way they do. It's almost magical. In case for Breath of the Wild, the art style allows you to use the lowest possible size of textures. It's absolutely crazy, did you know that Wind Waker HD is only 2.6 GB? Where Twilight Princess HD is 4.51 GB? Those are both decent size games in terms of length but the textures of Twilight Princess and minus the empty spaces make it much larger. Bethesda is also quite decent at compressing as well imho. They aren't as efficient as Nintendo, but they are within the realms of believability and attainability. I think Nintendo uses a lot of tricks in terms of known the own hardware that they created to offset some tricks. I mean Pikmin 3 looks beautiful in terms of graphics and textures and the game is only 3.85 GB. There are demos with much larger file sizes than that and look considerably worse graphically and in terms of textures. Textures are a huge factor in file size. This is why the HD era saw such a massive jump in file sizes.

tl;dr: Breath of the Wild is HUGE with it's massive 13.5 GB size in terms of Nintendo file sizes. They are very efficient when they compress their games and this is their biggest game to date by a long shot.

I don't get the flak for why people harp on game developers that produce for HD twins for not doing enough to keep game sizes smaller like Nintendo ...

It's not like their purposefully trying to stuff as much data possible when most of the time they don't use pre-rendered cutscenes, not trying out procedural rendering, not using texture compression algorithms (great idea for increasing performance) or not pack as much data as possible using different data formats ...

Nintendo gets the luxury of not having to mix HD textures, big levels/worlds, high amounts of assets, different mechanics and systems or making lot's of distractions altogether in one package ...

What it takes to make AAA HD twin games these days compared to Nintendo's AAA games isn't even in the same league in terms of man hours ...

It's understandable why AAA HD twins games are justifiably large when their market keeps expecting those production values and craftsmanship ...

What do you think is a fact, here?

Nintendo make big games that don't take much space?

Ever wondered why those games don't take much space?

I don't know how accurate your claim is. 

http://nintendotoday.com/breath-of-the-wild-development/

"Breath of the Wild took four years to develop and employed 300 developers at Nintendo.

That’s according to Zelda producer Eiji Aonuma, who has been working on Zelda games for 20 years."

http://www.gamespot.com/articles/this-is-how-much-the-witcher-3-cost-to-make/1100-6430409/

"The Witcher 3: Wild Hunt was developed over the course of three and a half years, with a total of 240 in-house staff working on it. "

And there are lots of reasons for that.

The Switch only has 16 Texture mapping units verses the Xbox One's 48, the Playstation 4's 72 and the Playstation 4 Pro 144.
The Xbox One's TMU's however operate at 853 - 914mhz verses the Switch's 307.2mhz - 768mhz.
The Playstation 4 and Playstation 4 Pro are 800mhz and 911mhz respectively.

Meaning in a worst-case scenario the Switch has a texture fillrate of 4,915.2 verses the Xbox One's 40,944.
Giving the Xbox One an 8.33x texture fillrate advantage over the Switch, the Xbox One is considered underpowered.

The Playstation 4 has a texture fill rate of 57,600 and the Playstation 4 Pro, 131,184, more than double the regular Playstation 4 and 26.68x better than the Switch.

Tegra can punch a little above it's weight thanks to it's tiled-based approach which results in more aggressive culling and less wastage... But it's not going to bridge that gap.
Whilst docked the Switch's fillrate will jump to 12,288, giving the Xbox a theoretical advantage of 3.33x.

Bandwidth is an issue on the Switch at 20 - 25Gb/s. (Thankfully Delta Colour Compression also increases the usable bandwidth.)
That will also impact texturing.

Result is, the Switch is not a texturing powerhouse... And it's not because of storage, speed or capacity or the lack of Ram.  - Although the Ram capacity could limit things as well, but I doubt it, streaming textures from a cart which has a ton of bandwidth compared to optical storage, can save a ton of memory.

Disclaimer: This is theoretical performance, not real-world. Numbers are meant as a guide only to give a rough idea.

It's sad, because if Nintendo wen't with a Pascal based Tegra... Texturing could have been increased by 50% without using a single watt of more power.

You could always go physical.

But the system memory seems to actually be on a diffrent, modular chip in the Switch, so it's possible that nintendo will come out with higher capacity revisions or that you could potentially stick your own chip in there down the line. Not ideal, but an interesting possibility.

I think you're right about Bethesda to be honest. As for the other part, well your mostly right. The time it takes to compress can be rather long and it's often done near the end, or much later in development. I had to compress a couple of games and it takes a while if you really want it to still look nice, it's quite heart crushing really, but it has to be done Q.Q  Some people really have too little of an idea how much of a difference it can make it making your games look crisp or blurry.

As for Nintendo I still think they use a lot of other tricks with their games to cut down sizes. For example like how they do the ship sailing in Wind Waker and create an illusion of traveling over the large waters. That saves a lot of data right there alone. I'm trying to find the behind the scenes video for that but I can't find it right now >.< Here's hoping you may have seen it, no? >.<

Looking at those file sizes, I might get Puyopuyo digitally too. It will go nicely with Snipperclips.

Well as expected, Switch just doesn't have enough memory to hold big digital games, 32gb... Definitely buying everything that's big Physical.