Communism is an economic system that is based on community and equality for all, where capitalism is an economic system based upon the rich and selfishness. Communism may never be true in practice (mostly due to past mistakes), but in theory it is the lesser of all evils that are economi systems.
Okay, this can be solved by one simple example:
I am a skilled worker. I stand to lose if communism is implemented, because I will have to support the unskilled workers under me because of my increased workload. Because I have more ability, I will be called upon to do more than they are.
Communism would stifle productivity.
Here's another example:
I'm a lazy bum. Hey, look at that skilled worker (above) busting his hump. I could sit here, do nothing, and still get a roof over my head, water to drink, and food to eat. I'll game the system and do just that.
Enough people do that, and the system falls apart.
The alternative would be forcing people to work, but that would mean that some people would be more equal than others.
Welp, free enterprise isn't perfect, but it beats that travesty.
Best we've come up with so far at least. Although communism is based on good intentions and might sound good on paper, no real world application has so far been successful and true communism have never existed. It is supposed to be leaderless and equal but has in every attempted case made it too easy for the wrong people to gain power. Thus, it’s faulty, or at least its fail-safes are. Look at “communist” China; it’s in some ways even more capitalist than the US, where the few rule the many, communism there is just a word.
Now, my above headline sets the tone for the following statement: Communism is idealistic, capitalism is pragmatic. Communism is against man's instinct to be greedy and selfish while capitalism appropriately appeals to such instinct. Considering history, Chairman Mao led the people by the sheer weight of his rhetoric whereas Deng Xiaoping led through pragmatism, achieving unprecedented growth through liberal economic policies and a deft hand at playing foreign relations. After all, the China that we see today is the product of progressive Chinese leaders like Deng Xiaoping. While Deng Xiaoping isn't the perfect embodiment of capitalism, he demonstrates a progressive attitude that is apt for this century. Communism is impracticable in application.
Communism will failed every time you use. Even if you were on a remote island with 5 people, it will fail. It's a idea of an utopia and utopias never lasts! Look at the Soviet union when it was communist, they had a feminine which killed 5-6 million people! The same with red China millions of people were killed.
The idea of redistributing all of the productive capital will fail too. Government feeds itself before its people!