North Korea has markets nowadays where currency is traded for goods, even if they also have government rationing and almost total government control of the economy. China does not only have markets where currency is traded for goods but also has the whole stock exchanges and billionaires thing. The democratic socialist states of northern Europe also follow capitalism, even if the government is heavily involved in both the economy and is giving out large amounts of welfare. Capitalism is very broad. You can absolutely be left wing if you live in the USA and want capitalism to work more as capitalism works in the Nordic countries. In a way you can therefore be pro capitalist and left wing. However I kinda get what the guy in the post means but I still want to be clear that you can be left wing and not want to abolish currency at the same time.