Questioning the intelligence of communists is incorrect. The Soviet Union, (although not a pure communist state in the Marxist ideal) was insane, not stupid.
"To each according to his need" is a fundamentally flawed concept in a technologically advanced society and that concept in a natural state causes sloth and crime. All one needs to do is look at what happens in a national park when wildlife is fed, rather than left on it's own to make their living.
Feed the bears, and they begin to live at the garbage dump and raid campgrounds. They become fat and diseased, and some need to be relocated or destroyed by park rangers.
Keep the bears fending for themselves, and they dine on elk, venison, and wild berries.
Apply this wildlife behavioral concept to people, and parallels can be found where government housing projects show some of the highest crime rates.
You do not have to look at the Soviets to see illustrations. The US county which has the deepest poverty, is traditionally the Pine Ridge Indian Reservation, South Dakota, where the government programs which “care for the Native Americans” have resulted in decades of abject poverty. Only with casino gambling has a semblance of self-reliance started to chip away at the tribal dependence on government and even the profits of the casinos tend to in large part go to off reservation shareholders.
Changing Pine Ridge to a vibrant economy will take hard choices, and the hardest but most vital choice will ultimately be cutting the umbilical to the Bureau of Indian Affairs.
The socialist mindset tends to keep throwing more government programs to solve the problems of the downtrodden, and in effect feeds the bears. Then when the problems do not alleviate, the problem was the program wasn't large enough.
"Insanity is doing the same thing over and over and expecting different results!"