Learning by mistake isn't painful; it is how you learn best. I keep iterating on that point to my children. But that isn't merely what these guys were doing. They were doing more, since they were documenting their (expensive!) learning process. Documenting your learning process and sharing it freely is allowing others to not make the very same mistakes, but to do better instead. It lowers the barrier of entry for competition, taunting competition who hopefully also share back. Like many talks on 39c3 (esp. the lightning talks), it is an invitation to collaboration.

Sharing the documentation is also an act of compassion, and very much in the spirit of FOSS & OSHW.

This talk was hands down my favourite talk (and not even in a subject I am familiar with!). These two guys shared a lot of info in little time, and were very humble. It was also a presentation which contains a political component (Europe's lack of independence, specifically hardware-wise), but it managed to avoid that discussion. Why, because it is assumed the attending public shares the same value. Instead, it maintains focus on the taking action part. I am not sure everyone here shares said value, but I do, and for whatever it is worth: USA is in a similar boat.