The key word in the OP's argument is yet. I agree that bitcoin is not at the point now that someone can receive it for some good and then go buy a totally unrelated good at the market price. We are however getting closer to that point. What is stopping the "loop" from being possible is the lack of merchant adoption and the lack of b2b transactions possible with bitcoin.

We have however seen increases in merchant adoption with many major businesses starting to accept bitcoin, and some with a policy of retaining some of it to spend later and some with a policy to have all their expenses denominated in bitcoin