Socialism is a kind of a pipe dream it just cant work unless God is running it. Men tend to become corrupt over time unless there is some kind of system to keep them balanced. That is the problem with the government and elected and appointed officials. As long as it is someone else's money it leads to corruption and ruin. People always want more and more till the whole system collapses. That is socialism. Argentina and Detroit and Greece and Spain are all good examples.
You are right, but capitalism suffers from equal problems. People will seek to exploit any system of government for their own benefit. Think of all of the money spent by corporations trying to gain tax benefits or contracts by lobbying and bribery. Think of the monopolies and price collusion that has happened. Arguing that one principle of governance is superior by pointing out the weak points of the other is pointless and not relevant to the idea in the OP.
For my part, I think that neither capitalism nor socialism will exist eventually, as they are means of distributing scarce goods. When our society generates goods in sufficient quantity to satisfy its needs without human effort, the government will instead focus its efforts on meeting other standards of human actualization. But until then in the US capitalism will exist, with an increasing shift of social welfare programs to support those who are not needed for their role in the economy. The people who continue to add value will continue to work.