You can buy a 17 foot travel trailer for less than $15k and it includes a toilet, shower and cooking facilities. Harder to ship in bulk but I bet you can get it delivered anywhere in the continental USA for less than the $2.50/mile Jupe is charging.
The plan was to make it as affordable as possible.
The conclusion I eventually came to was that to get to a remotely reasonable price point (around $10k at the time), anyone motivated enough to pursue this would probably find better solutions on the market-- like your example of a travel trailer.
Whatever these guys are doing is nowhere near that and not what the headline made me think of. It's definitely not going to help anyone who doesn't already have tons of other options.
The exception is the people who want to do that, and don't know anything about it, and would pay $10k for such a thing, set it up in the woods, and get eaten by a bear, fall down a ravine, or eat some poisonous flora on their third night.
I think you're right that it requires a certain amount of intense interest and preparation, and that people who are up for it will likely prefer a personalized solution over a pre-designed kit.
Perhaps it could still be viable as a service, where you help aspiring off gridders avoid common mistakes? Probably a tough sell regardless, but I wouldn't rule it out. I continue to be enthusiastic about the general idea.