Humans are at their very basic nature, capitalists. We buy and we sell, and when we do that we try to sell at the highest price and buy at the lowest price. Underlying every economic system, from laissez faire capitalism to communism is the reality that the underlying human nature of the people within that system will not change,they will only adapt those same tactics to function within that system. Economic systems may come and go, but people do not change.
The Soviet Union took away land and private businesses. It drastically limited employee salaries and collective workers' access to produce. It drastically centralized the economy and removed individual freedom. What it created as a result was a "Black" economic system in which most of the production and even office resources such as pens and paper, were stolen and sold or bartered on the black market. Soviet diplomats and Olympic athletes returned home with massive amounts of items bought in the West, to be resold on the black market. Decades of executions and gulags, campaigns that worked to convince schoolchildren to inform on their parents, made no dent at all in the problem. Everyone stole, and the reason they stole was that it was the only form of individual economic initiative that was available to them.
Communism is the most extreme example of government nationalization and centralization, and yet it could not control the free market operating within itself. Having made legitimate economic transactions illegal, its entire economy became illegal. The promoters of Communism boasted that it would insure that everyone would have equal access to the same goods and services. Instead goods and services still went to those who could pay for them, through bribes and black market activities, only those activities were no longer taxable. What happens to a government whose economy that is mostly illegal and untaxable? Within two generations the Soviet Union had become dependent on imports for everything down to food and clothing. By contrast China revised Communist dogma to legalize profit seeking behavior, resulting in a massive economic boom.
Socialism is commonly implemented with promises that it will be fairer and make resources available to more people. Yet the two-fold problem with socialism, is that socialist systems actually consume resources inefficiently, thereby limiting the resources that are available, and that government controls actually drive spending into an untaxable and uncontrollable black market.
Setting a price ceiling results in shortages, as numerous socialist systems have demonstrated for us, most recently Chavez's Venezuela. Price controls decrease production incentive and push more goods into the black market, while sharply decreasing the quality of goods available on the legal market.
Attempting to cut costs routinely bypasses the actual "fat" within the system, namely unions, bureaucrats and over regulation, all of which are key parts of a socialist machine, instead targeting producers and consumers. Targeting producers reduces quality and availability. Targeting consumers results in rationing. Either way the end results lead to shortages of vital goods and services.
Socialist solutions promise to extend services, but they can only do so at the cost of cutting quality and creating shortages. Rather than addressing the reality of this, they instead trot out propaganda blaming producers for the high cost of services, resulting in crackdowns that worsen shortages and the quality of the services being provided. The follow-up "Soak the Rich" arguments push for higher taxes, but government spending on social problems will sooner or later outpace even the most aggressive punitive tax revenues, because unlike legitimate income, government spending has natural stopping point except absolute insolvency, and because raising taxes drives out the very people and businesses who are supposed to pay for the programs, killing the golden goose of capitalism, only to find that its socialist parasite can't live without it.
And at the bottom of the whole pile of problems, is the question of who actually needs socialism. Its proponents are usually upper class or upper middle class, who want it to be available for the poor. They want public housing they wouldn't live in. They want health programs they wouldn't use themselves. Public schools they don't want to send their own kids to. And free food they wouldn't eat themselves. Naturally they don't want to pay for the whole thing either. They want the "other rich" people to do it. The bad rich who don't care about poor people, the way they themselves do.
For the upper classes, economic or ecological morality hold the same role that sexual morality does for hypocritical clergy, it's very well and good, and they're happy to sign on to it... for other people. So you'll find the same entertainers demanding higher taxes to feed the poor and clothe the hungry, have their money tied up in complex ways overseas and out of reach. Because they mean for someone else's money to do all those things. Not their own wealth. This makes them hypocrites, but it's also a reminder that human nature doesn't change. Scratch the long-haired musician calling for everyone to give up their money for Africa, and you'll still find a capitalist inside.
On the other hand what the people socialism is meant to serve want is a social safety net, but without compromising social mobility. Because while the upper classes may toss down a few crumbs, what most people on the lower part of the ladder want is to climb up. Because after all they're capitalists too. They want their children to be better off than they were, not simply through social safety nets, but through hard work and effort. And those who don't want to climb up, have been severely damaged by living under a socialist system, to the point that the only thing they want is to live in a box and be taken care of by the government, generating a self-perpetuating social problem for government bureaucracies to gleefully cackle over.
The more government centralization there is, the less opportunities for social mobility remain. Climbing the ladder only has meaning, if there is a ladder. The more small businesses become unfeasible, the less room for social mobility there is. The sons and daughters of hardworking fathers and mothers are instead directed to take exams and climb into the echoing steel womb of the government bureaucracy, where they can look forward to pushing paper around a desk for most of their lives, and possibly earn a little extra on the side, if the situation has become extreme enough for a bribe economy to develop.
Philosophers and courtiers have spent a long time dreaming of the perfect state, only to generally conclude that it cannot exist. Because people are not perfect. The great socialist dream of a state that will care for everyone and do everything only functions on paper. When it is implemented in real life, the realities of running a large system ripe with bribery, corruption and inefficiency quickly make a mockery of all the paper plans. And the more the system squeezes people, the more it begins working against the people, putting in motion the very social and economic forces that will finally destroy it. There are few inevitable things in life, but human nature is one of them. And if you bet against human nature, you will lose. And socialism, which insists on betting against human nature, will continue to lose.