if a good idea fails over and over and over in practice
it's a bad idea.
The problem with Socialism/Communism is that in reality this always turns out as things being "planned" and run by the government.
In practice this has always proved to result in both corruption and incompetance.
As an outsider - I would say that the USA has a relatively good system of democratic government - but still has an abysmal record of inefficiency in economic activities directed by the state - with also some successes where policies have used market mechanisms.
In some ways democracy can make this even worse. You only have to look at the way the political influence of midwest farmers kept in place the crazy policy of turning valuable food into fuel - which without government subsidy would be totally uneconomic.
While the market mechanisms used in the USA Sulfur Dioxide emissions trading scheme seem to have been fairly successful.
Where Government intervention (which is always a form of Socialism) does help is in enforcing rules, making sure "externalities" are paid for, enforced spreading of risk and protecting the weak or less able.
The "Invisible" hand of the market needs strong propoerty rights, rule of law and also direct action against monopolies to work properly.
The cost of Externlities (like poultion) need to be paid for by those that cause them - so that they are either minimized or only caused by things that have very high ecconomic value. Only Governments can enforce this.
The costs of risks which society as a whole can't stand by and see people suffer from need to to be spread - hence the "Socialist" concept of compulsory health insurance.
If you are not prepared to have people dying for lack of health care - everyone needs to be forced (if able) to pay towards the cost of this.
The most obvious example of protecting the weak is to ensure children are cared for and educated - no matter how unwilling or unable their parents may be to pay for this.