They sounded like a made-up story until I started to look into what you were saying. Why does this family do this? What's the motivation? Pure hacking? Do they run a business in technology and they play around with fun side projects like this?
Why did Mozart write music? What would Mozart have done if he lived in the city of the deaf?
I mean they've written a lot of stuff on their web site about their motivations — they saw that electronics were the wave of the future, they wanted to make Mexico technologically independent and limit the damage of the neoliberal economic model, they wanted to preserve the Zapotec culture from obliteration, and so on — but I think basically it's that they like doing it, in the way Mozart liked music. I'm sympathetic to those other motivations but I don't think they would have been sufficient to maintain their progress in the face of the opposition they've faced from the Mexican government, which continues to adhere to the obsolete "progress is big factories" model mixed with the simply traitorous "progress is installing Microsoft software" model. (They've written about this stuff on their website too.)
As far as I can tell, they make a living by building some industrial control hardware and teaching electronics classes. Maybe a member of the family will comment and offer more detail.
If the OP that posted the link here is the same person that wrote it, as their username and comment history suggests, I think you are probably spot on wrt being motivated by doing it for the sake of doing it.
The HN profile of OP says: “I fight boredom by challenging myself to my limits.”
