Why Is The Left Pro-Inflation?
For many, the primary reason is that they are ignorant about the redistributive effects of inflation because they cling to what I think should be called the "Scrooge McDuck myth". They believe that the rich is like the fictional character Scrooge McDuck, with all of their money in the form of physical cash in a large money bin., who will lose if the purchasing power of money falls.
Yet in real life, it is probably not much more common for the rich to hold a significant part of their assets that way than they share another of Scrooge McDuck's characteristics, namely being an antropomorphic duck. Instead, they hold most of their net worth in stocks or other assets which benefits from inflation.
The other important reason is that inflationary policies strengthen government, and for many leftists that is more important than equality.
The most important way inflationary policies both strengthen governments by making it cheap for them to engage in deficit spending when the central bank buys their bonds with money created from "thin air".
Furthermore, if inequality is increased, especially in the form of making already rich Wall Street bankers richer, then this will strenghten the case for more redistribution from the government. Thus, some of the leftists who understand the effect of inflationary policies but views big government as more important than equality, this may be another reason for them to support, even though they are unlikely to make that case openly.