I'm afraid Bitcoin will hardly ever be adopted as a medium of exchange. Why? It's too slow and expensive to pay for everyday stuff. And that's completely fine. Bitcoin is a non-correlated asset that is beginning to take on the role of digital gold. There are many other coins much better at being used as everyday payment systems. One such system could be STEEM, or rather, SBD. Steem is a DPoS chain and thus vastly more scalable than any PoW chain. Less secure, sure, but good enough for paying for your coffee. Powering up a multi-sig account controlled by a smart contract that prevents taking back upvotes would enable one to even pay for a hamburger with an upvote!