Can you answer why Communism is completely wrong... and if so, is it moral to buy Chinese products?

From what I read, people here use Communism, Socialism, Capitalism like they are set in stone or curse words. Seems to be little regard that those terms started as BOOKS and theories, many years ago. Later countries adopted those theories, and what we have now is a modern world, and an opportunity to follow the best ideas that work for US. To cling to these words makes little sense accept to use them to slander, or as twisted propaganda to manipulate uninformed people.