Why socialism is so popular?

Von Mises Blog on socialism:
"One may wonder whether Sir William Harcourt was right when, more than 60 years ago, he proclaimed: We are all socialists now. But today governments, political parties, teachers and writers, militant antitheists as well as Christian theologians are almost unanimous in passionately rejecting the market economy and praising the alleged benefits of state omnipotence. The rising generation is brought up in an environment that is engrossed in socialist ideas.

The influence of the pro-socialist ideology comes to light in the way in which public opinion, almost without any exception, explains the reasons that induce people to join the socialist or communist parties. In dealing with domestic politics, one assumes that, "naturally and necessarily," those who are not rich favor the radical programs — planning, socialism, communism — while only the rich have reason to vote for the preservation of the market economy. This assumption takes for granted the fundamental socialist idea that the economic interests of the masses are hurt by the operation of capitalism for the sole benefit of the "exploiters" and that socialism will improve the common man's standard of living.

However, people do not ask for socialism because they know that socialism will improve their conditions, and they do not reject capitalism because they know that it is a system prejudicial to their interests. They are socialists because they believe that socialism will improve their conditions, and they hate capitalism because they believe that it harms them. They are socialists because they are blinded by envy and ignorance. They stubbornly refuse to study economics and spurn the economists' devastating critique of the socialist plans because, in their eyes, economics, being an abstract theory, is simply nonsense. They pretend to trust only in experience. But they no less stubbornly refuse to take cognizance of the undeniable facts of experience, viz., that the common man's standard of living is incomparably higher in capitalistic American than in the socialist paradise of the Soviets."