The backend is more complicated, involving databases that determine your creditworthiness, plastic cards, communication networks, monthly billing, fraud prevention, ...
All those things will happen to bitcoin if it ever gets anywhere close to being used as a real world currency.
You're comparing a completely regulated system against a completely unregulated system, one which also happens to be brand spanking new.
You're also bringing lines of credit into this for some reason, if you think people are just going to hand you out free bitcoin for your to pay back at a later date without wanting to know your credit worthiness I'm not sure how to explain things to you in a way you'll understand.
