> Personally, for privacy reasons I do not want to leave a footprint in the blockchain for each pizza. And why should this expense be good for trivial things of everyday life?
Then what's the point?
Isn't this supposed to be an Open transactional network, it doesn't matter if you don't want that, what matters is what people want to do with it, and there's nothing you can do to stop someone from opening a wallet and buying a pizza with it, except the core of the problem you ask yourself about, which is, the minute this goes mainstream and people get their wallets out the whole thing will collapse, regardless of what you want the blockchain for.
Why talk about the billions of unbanked and all the romantic vision if you can't let them use their money however they want in a decentralized fashion. Otherwise let's just go back to centralized banking because the minute you want to put things off chain, you need an organization that will need to respond to government regulation and that's the end for the billions of unbanked to be part of the network.