Communist societies can't compete with free market capitalism and resorts to mandates in order to eliminate its competition.
In other words, landlording cannot compete in a communist society, hence the claim must be made that the communist society is to blame.
There is no such thing as "free market capitalism". Capitalism, like communism, requires certain rules that make any market un-free.
Try to imagine a capitalist society that does NOT _force_ people to accept a certain set of property rights. It's impossible.
Both systems have to force people to surrender to its rules. Whether these rules are called "the will of some god", "the will of the people", or "natural rights", doesn't matter.
Let's say we are a primitive society consisting of nomands that just start to farm. How do you make it a capitalist society without _forcing_ me to accept that, suddenly, land that I was allowed to roam freely on is "yours"?
If you do force me to accept your new rule, you have just forced capitalism onto the free market.
It doesn't matter how old and established the rule is. If you need force to apply the rule to people that disagree with it, you cannot claim that your system is a "free market".
BTW communist societies can compete with capitalist societies very well. Just imagine two families, one run as a capitalist society, one as a communist society. Guess which survives longer. (Hint: it's the family that applies "from each according to his abilities and to each according to his needs".)