Capsule is far more expensive over the it's lifetime than something like a Gaggia Classic. Capsules aren't anywhere near the quality of coffee shops, unless you're counting Dunkin.
Nitpick on your nitpick. While the word originated in Italy as espresso and that is mostly what we use in the English-speaking world, expresso is not totally uncommon and it's not necessarily a misspelling or folk-etymological error. French and Portuguese use the expresso variation for instance, and the x spelling is considered 're-latinized'.
Depending on where you live the beverage may have entered your culture via French or Italian influences, perhaps one reason why expresso seems more common in Canada than in the US (though espresso dominates in Canada as well, no doubt helped by the ubiquity of Starbucks).
To add on to this - many offices replace their teas with Keurig capsules as well. This leads to a tea that's much more expensive (capsules are something like 4 or 5 times the cost of a tea bag), dirtier, more complicated and more time consuming to make.
Looking at the popularity of Keurig machines, I'm not surprised people saw potential in Juicero.
Portuguese is my first language, and I never even noticed it's written differently in English. Noticed now.
As I said in my gourmet item, it is not something that correlates perfectly with quality. It may correlate better with price than quality. It's a property coffee shares with wine.
The cheaper capsule machines are about the same price as the cheaper non-capsule espresso machines.
It's true that the high end of espresso machines goes well above the high end of capsule machines, but that doesn't seem particularly relevant.
If you look on gumtree (like craigslist here in Australia) by far the most common appliance item by a very large margin are basic juicers. People like the idea, but in practice they go un-used because they're a pain to clean and people can't be bothered.
Best I could tell that was the same idea Juicero was after.
I get my beans whole, by subscription, grind them myself just before making an espresso. Another advantage of starting from the beans (apart from something that is actually pleasant to drink) is that you can select lots of other brewing methods, whether it's aeropress or moka pot, cafetiere or filter, with different grind levels as appropriate.
Also if you like milk-based coffee products (where the taste of the coffee is far more diluted, and the quality is less relevant), having a steam wand is handy and much better than any attachment I've used on any coffee machine, including Nespresso, and other much more expensive models that do bean to cup.
- Expressos are minimally hard to make correctly, and those capsules are above even the quality of some coffee shops.
- There is a big movement of gourmet coffee that favors high priced drinks with the correct marketing (not perfectly correlated with quality).
None of those seem to apply to Juicero. They may have aimed at the last point, but I don't think it's something you can create on a startup's budget.