If one does a Google search for why Communism is appealing to some, the results, like most Google searches, are underwhelming, full of low-quality Quora links and other crud. No one can provide an adequate explanation for why Communism, but also Nazism and other totalitarian ideologies, are appealing to some. How could anyone support these ideologies, that have caused such great death and suffering in the 20th century? How can this be rationality justified?
Some common but wrong explanations are:
Laziness, such as people wanting free stuff provided by the ‘productive class’. I disagree with this explanation. Academia is full of left-wingers, yet the highest echelons of academia are very competitive. Getting tenure is even harder than becoming a CEO in some instances. People who are lazy are either unemployed or work at some low-paying service sector job. They don’t go into academia or non-profits. It just seems like a reductionist explanation that does not account for why many upper-middle class people hold far left-wing views.
Another common but incorrect explanation is ignorance. I disagree with this, too. The awfulness of Stalin is almost a meme by now. I find it hard to believe that people are not aware of how bad Soviet Russia was. Ignorance does not account for educated people supporting Communism.
Nazism and Communism are similar in some ways, such as economic populism, but distinct in others, such as Communism being more inclusive. The economic populism of both ideologies makes them appealing to the lower and middle crusts of society. To answer the original question, the support of such ideologies, imho, is rooted in evolutionary reasons, as a way of improving one’s own ‘genetic fitness’, which is sorta ironic given how many deaths these ideologies have caused. There is a belief, perhaps almost a paranoia, that if some individuals or entities become too powerful they will consume all available resources, be it social, economic, or even reproductive, and leave everyone else with little. Communism and Nazism, with their emphasis on economic and social control, are ways of reducing such inequality. At the cost lower standards of living, by flattening the wealth/social pyramid into a single homogeneous ‘brick’, everyone is assured something, because there is nothing that differentiates anyone from anyone else. That means that individuals with low fitness could stand to gain.
Also, some people hold fairness as being paramount, and rationalize it is better to have equality even if it makes everyone worse-off in terms of economic utility. Perhaps academics rationalize that under a Communist government they would have more power, with the wealthy business elite bearing the toll instead of the intelligentsia, although the most extreme forms of Communism did not spare intellectuals (there is a stark difference between the Khmer Rouge and the USSR despite both being under the umbrella of communism). Perhaps there are two fundamental views that shape how people perceive the world: one based on opportunity and the other on equality, with the latter being more receptive totalitarian ideologies and the former supporting more individual autonomy, being closer to classical liberalism and conservatism.