>> I would love to know which societal problems can be reduced to a distributed trust problem. That would convince me that I'm wrong about blockchain technology.

I feel like Namecoin, the first Bitcoin fork, is ready to replace our current DNS system. The transaction fee for registering domains is comparable to current prices, and it gets us out of this horrible situation where we trust companies and governments not to abuse their power and sign new certificates (this is not just a theoretical issue). The problem of associating signing keys with domains is about as basic as you can get with distributed trust systems.

Are you unconvinced by this use case?