Kind of like how the local church might traditionally manage birth/death/land records, but that doesn't mean the documents are sacred or a religious observance.
Well I mean technically they are always for credit purposes, even if they are the "default/convenient payment method"? That's part of the advantage, but it's still credit. You get to spend and pay later. It wouldn't be a very good evaluation for credit purposes if it didn't work like credit? Or am I misunderstanding you?
It's just to say that "credit" isn't just about an in vs out group anymore than debt is. Or anymore than "currency" is? I'm not sure how the distinction you make helps clarify that question. The point is why would credit be for people you know, and currency for people you don't? Isn't credit just a particular agreement around said currency?