You cannot produce value from thin air. When they produce that money, it is a form of taxation because it decreases the value of the previously produced money. Monetary inflation devalues the currency.
Even if true (which, its not, value is created "from thin air" all the time; otherwise, wealth would be zero-sum, and per capita wealth always declining with increasing population), this is irrelevant to the upthread claim which was that governments do not create money. Which is quite obviously false.
- Governments literally stamp their names and politician's faces on money. You're supposed to obtain it and give some back to the government.
- There’s a distinction between government and economy, though government enforces capitalism (social relations of "property", police, etc), and attacks other nations which try alternatives.
- The money supply is basically bureaucracy-points made on computers.
"In God We Trust" is an apt description of how we're not supposed to question simple things. With the moralistic notion of "debt", we religiously consign children to awful fates.
Money is just a reflection of production (i.e. scarcity of production). Due to market forces inertia, monetary supply can be manipulated, but you can't just start printing money left and right without causing inflation; there is a hard science of doing it without disturbing market balance.
The value ascribed to money is, of course, related to what it can be used for and how much of it is floating around, and production in the area where the particular form of money is the preferred medium of exchange is one of the factors that is relevant to that. And, perhaps the statement about governments not creating money meant that governments don't create value. Which would still be wrong, but in different ways.