Memes

Actually, if we go by the name, then the defining trait would have to be the use of capital as a means of production (i.e. capital producing more capital all on its own). In other words, usury.

You are correct that commerce or a free market aren't exclusive to that system. Nor is usury required to have a free market exchange of goods. But when you combine that with a market for capital, it kinda puts the whole thing on steroids, because it introduces massive amounts of leverage, and with that, all kinds of speculative activity.

If you don't have access to capital markets, the only thing anyone can invest into anything is their time. And everyone gets exactly the same amount of that, 24 hours each day. Of course that doesn't mean that the results will be just as equal, but there's only so much you can do to multiply the productivity of your time, so the results will probably be in a more narrow spectrum overall.

However, if you can get access to massive amounts of cash at the stroke of a pen, you can effectively buy a lot of time from other people who are wiling to sell theirs, but since you have to pay that money back with interest, you are now forced to make them deliver more value. What if THAT is actually what's causing the kind of exploitation that communists are lamenting, and they're simply misplacing the blame from those who are running the game to those who are merely playing it?