I wonder whether "digital packratting" (collecting e-books, scanning everything to Evernote, collecting gaming "trophies") can replace the hoarding need that is so important to many people, but without the downside of being burried in clutter.
I think clutter is some kind of vicious circle. Once you start, it's hard to stop. And starting is pretty easy if you're not really vigilant -- things like long work hours, kids and long commutes quickly start your hoard. And if your life doesn't work out the way it does, you're prone to nostalgia and memorabilia.
Smaller accommodations make it harder to start that. But there's small, and there's tiny...
One thing I like about it is how easy it is to completely clean the house from top to bottom. But no place washer and dryer. I think it would be cool to have one as a retreat.
Also, for ecological reasons, this would still be a waste of space, as you're only using two dimensions and probably need some space around the building. A typical apartment building would be better.
This is quite good if you've got a lot more land, but only a little space to build upon (forest, hills, etc.).
If I remember correctly, even the founder of the company selling those houses only partially lives in one of them. He's got a bigger, traditional house next to it.