If inflation is a non-issue, why do they prosecute counterfeiters?
Earnestly, or is that a standard quip, or leading into a bad faith argument..?
First and foremost, the government reserves the right to that, for better or worse. As the government has a monopoly on violence, for better or worse, so too on the money supply.
Also, they likely didn't understand the systemic effect of counterfeiting, at the time such laws were written. At least as we understand economics today. It's simply traditional that sovereigns have a right to mint/print their own money, and to authorize and enforce its common use.
So, that's a sufficient explanation alone, but doesn't address the point in context.
As for that, for the systemic effect of counterfeiting: if there's no penalty to doing so, then the money supply is completely unregulated, and in particular there's no cap on it. So everyone just prints whatever they need for the day, say, and repeat ad nauseum. What would that even look like... I guess, common people (without printers) would be screwed, having to get second-hand bills from sources, therefore at considerable expense (inflation); while the larger economy (i.e., mostly that of capital -- specifically, those who own printers, especially lots of them) operates much as it does today, but not in terms of face value of bills, but on a more basic level, such as the amount they are able to produce -- regardless of the face value, which is always going up exponentially (and who's to say what denominations are legal tender anymore, who could keep track of them?) so really doesn't mean anything at all, and it's actually a transformation of the real material value of the resources used to make it (capital, paper, ink, energy).
So, a similar function as trading barrels of oil today.
So, clearly, some authority needs to say, nah you can't do that. People will naturally do this, discarding the "official" bills, resorting to trading more stable stores of value; and, basically we're back to barter. Perhaps a harder-to-fake medium will be discovered/developed, and that'll last as long as it takes for everyone to retool their printers, or obtain the raw materials, etc., and then it's a race to the next medium and so on. (We've seen this multiple times in MMORPGs where money farming exploits have been repeatedly discovered.) That's a very... emergent or anarchist sort of approach. Or perhaps enough people will get together, to effectively ban counterfeiting, nominating an exclusive and controlled source, and prosecuting violators. Well, then you'd have more or less what we do, give or take how many people have really agreed upon this thing we call "government".
Put another way: I put a regulator on my power supply because I need to
add or remove controlled amounts of charge to the system, I can't just plug it into the wall outlet and go. A regulated money supply can be adjusted
up or down, while a truly unregulated supply, basically can't even exist as such anyway.
Tim