That's very easy to answer. The problem is that capitalist society TEACHES selfishness. Socialist societies teach altruism. No society is perfect, because humans are generally dumb asses who could not behave like decent animals to save their lives, but teaching good or bad behavior is the biggest difference. Then you have the US government always parading and bragging about how good their government is, but when people have to brag about what they have, it usually means something quite the opposite. When the USA feels like it has to invade countries to bring about changes, it is because they can't sell it to societies. If the US government was such a shining example on a hill, they would not have to invade and destroy nations to force others to follow their way of government. Socialism does just fine when it is not trampled on by the idiots in Washington. They don't seem to want to invade China or Russia to change their governments though, because deep inside, the Washington capitalist idiots know they are cowardly selfish pigs, and would not undergo such risk to themselves. With regard to work, Russia and China both modernized in a very short time compared to many other societies, and that does not happen without work. Work for socialist societies goes back to the idea of being taught standards for society, like social responsibility over egotism, and work for the common good of society as a whole. The reason why capitalist pigs do not understand this is capitalism is all they have ever known.

The selfishness and greed are the reasons cap’ism does work.

Stupid straw man argument, a hallmark of the right.