Wouldn't it be great if everyone shared and was nice to everyone else? Well, obviously, it would be great. The problem is there no way to make it work.
And why is that? It's because people are basically selfish. Despite some praiseworthy exceptions, they look to their own interests and those near and dear to them before they worry about anyone else. If giving to people who needed it was as common as not farting in a crowded elevator no one would make a big deal out of giving to charity.
For 99% of our species' existence, people lived in groups rarely exceeding about 200 individuals. All of our social instincts are built on the experience of living in small groups. In fact, anthropologists have found that most people can only keep track of about 200 people at a time. How many people do you know on a first name basis? I'll make a bet it isn't more than about 200. It is hardly the suprising that almost every political movement uses kinship terms like "brother," "sister," "father," and "mother." In fact, every group today, however large, is structured like a family- be it a street gang, a cult, or a political party.
The beret-head crowd can bray all they want. Socialism has been a catastrophe in every country it has been tried in. The only country that comes close to making it work is Sweden. It has a high standard of living and lower inequality than many other rich countries. And what is the basis of Sweden's prosperity? Privately-owned industry. The only way to pay for public goodies is to heavily tax a robust economy. Social programs cannot work without capitalism. Capitalism cannot work (ethically) without social programs. The Swedish welfare system and those of other countries did not appear overnight. They are the result (largely) of workers demanding fair treatment by use of strikes and boycotts, a fact which is curiously down-played in many history books.
Marx was right when he said that labor is the foundation of wealth. If people refused to work to make others rich or without getting a fair wage, I imagine these defects of capitalism would quickly be fixed.