Let's look at money more closely and understand it.
Because of INFLATION!!!
Countries that supply money based on how the economy creates it are less likely to put an oversupply of money into the economy and cause inflation. The way the United States puts money into the economy is through distributing money by loaning it to banks through the Federal Reserve at a particular interest rate, (Federal Funds Rate). The banks then lend the money out into the economy via loans with an interest rate that provides a profit for themselves as well as being able to pay back the Federal Reserve Bank who they borrowed the money from in the first place. People and businesses use the money that they borrowed from banks to either make more money (the creation of money from less valuable things) or they work to get money to pay it back to the banks with interest (people receiving the benefit of the creation of money in exchange for their labor towards its creation).
Money is created by creating more valuable things from less valuable things. For example pottery is made from low cost clay, originally crops are made from holding back seeds from a harvest away from consumption, planting and adding water and sunshine, and then sold at a higher volume and value to consumers. Those are two clear examples of how money is created in the economy.
If the government just prints money and enters it into the economy the value of it has, has no economic creation point. Since the government can simply print more money if money loses its value against goods and services, it can simply respond by printing more and more money to counter the affects of inflation on itself. While, this may be true for governments it is not true for ordinary people and businesses. People and businesses can't do that. They will have to charge more and require more and more money for their services. This all becomes a downward spiraling feedback loop of ever dropping value of money.
We don't just print money because in history we have experienced the very same thing many times. Most famously during the German Weimar Republic time just before the Nazis took power. In the Weimar Republic as a response to the US banks calling in their loans during the Great Depression the Republic printed money to cover its expenses, which lead to hyper inflation and the money ended up being worth less than the paper it was printed on. Famously, Germans used the paper money for heat since it became less expensive than using it to purchase firewood or coal for the same heat.
MMT is not possible without the threat of inflation or worse hyper inflation. Historically, that approach brought on fascism. Maybe if the money were backed by a variety of substances that maintained their value against inflation then the distribution of money into the economy the non-Federal Reserve way could be possible... maybe, but you would need a lot of stuff to back the value of the amount of money in our economy and there still wouldn't be a method of accounting for the creation of money from selling high value products made from low value input products.
In conclusion MMT brings on the possibility of the collapse of monetary value, which is historically known to have brought on the worst examples of fascism. Why is the left so afraid of MMT? They are right to be afraid of it. Very afraid.
