Do tell.
Really? How?
> If you printed your way out of debt that would be a default in all but name.
Oh, right, actually they don't. So in fact it is actually impossible to default on debt in your own currency and you're admitting as much.
> You would cause a collapse of credit and a collapse in confidence in the currency itself.
Right. And a reduction of value of a currency is also called inflation. Which is pretty well accounted for within the discussion.
"why it's a bad idea"
aka, inflation. Which MMT spends a lot of effort modelling.
The conventionals recognize this too:
> With everything else going on, I really don’t want to spend time arguing with the Modern Monetary Theory people; after all, we agree on basic policy issues right now, and they are never likely to have as much destructive influence as the deficit scolds. But the MMT people think they have an argument with conventional Keynesians like me, and as long as they’re out there claiming that standard macroeconomics is all wrong, I guess we need to respond.
* https://www.nytimes.com/2019/02/25/opinion/running-on-mmt-wo...
> MMT says that, contrary to appearances, banks don’t make loans out of deposits. Rather, they make loans based on the demand for borrowing, then the borrowers stash the proceeds in the bank. Anyone they write a check to simply makes a deposit in another bank. The bottom line is that loans create deposits rather than deposits creating loans. This is one aspect of MMT that even some conservative central bankers—including those at Germany’s Bundesbank—agree with.