|Source: Reason Magazine-|
If you're a Socialist especially a hardcore Socialist who looks up to people like Che Guevara and even have some respect at least for some aspects of communism, even if you don't like the authoritarian aspects of it, Ayn Rand literally is the devil. Because she represents everything that you hate. Freedom, individualism, free-thinking, the belief that people should actually be able to make a living on their own and not have to be babysat by government.
Because if you are a Socialist who puts all their political eggs in the basket of big government like a wishbone offense in football that if they can't run the ball, they literally can't move the ball, because they have almost no passing game to speak of. And if government can't solve problems, by itself those problems don't get solved according to the Socialist. Because the socialist philosophy of socialism is completely centered not around government or even big government, but big centralized national government. Where even state or provincial government's, as well as local government's, barely exist, because so much power in the country is centralized with the national government.
Because Socialists tend to see freedom as dangerous and individualism as selfish. That if you give people the freedom to manage their own economic and personal affairs, you're only giving them the freedom to make mistakes that society (which is government, according to the Socialist) will have to pay for. Also, is you give people the freedom to manage their own affairs, they might become good at it which is what adults tend to do and not need or want government to take care of them and be less incline to have your tax dollars taking care of people who aren't as free as you. Socialists tend to see people who don't think like them at least, if not people in general as idiots. People who need help tying their own shoes and even spelling their own names. Who need big government managing their lives for them.
Socialists also see individualism as selfish. This idea that people can go out in the world and be creative, think for themselves and create new things. Is like trying to explain calculus to a fish. Its so foreign to them and would be like an American who has spent their whole life in America, who only speaks English and one day finds them self in Mongolia. It would be like being on another planet for that person having no idea what people are saying or even what language they're speaking. That is what its like trying to explain freedom and individualism to Socialists. You might have better luck trying to teach your dog to speak Chinese. Because freedom and individualism, completely goes against everything that Socialists have ever believed and have been taught.
As much as the Christian-Right hates feminism and freedom and equal rights for women, as if women are human beings who are capable of making their own decisions and living their own lives and deserving of equal rights as men, thats how much Socialists whether they're democratic or communist, hate Ayn Rand. Because they see her as the devil who represents individualism and freedom. Which to them is as bad as cancer or stealing. It completely goes against what they believe in and what they've been taught as people.
Reason Magazine: John Stossel- Ayn Rand: The Author People Love To Hate