Absolutely not! …unless there are consequences.

OR IS IT MORAL

Did you know that banks are creating money with your signature when you take a so called "loan"?

You have nothing to pay back, is already paid.

Don't believe me?

Just send them a letter asking to prove from where they give you those money in the first place.

Or just "pay" them back with a piece of paper, saying "this paper have the value X".

It is immoral to inflate the money. Paying back the loan is preventing inflation, this is called "elasticity" of money. Defaulting on a loan is stealing from everyone.