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.
Yea, it seems that subtelty might be lost in the title of the thread ;p or maybe there's an existential aspect here...
If a tree falls in the woods and no one is around... Is it a person when the sperm meets the egg...
Is a currency a currency before everyone in your own personal day to day life accept it?