The thing that communism didn't get is that people work harder when motivated. Communism just wasn't that motivating. I'd rather go to the beach. Capitalism holds a reward out there for working harder. Maybe some get it, maybe some don't, but it's out
there so more people work harder under this system.
If you don't understand how people think and how they'll keep adding value to society over time you'll never grok why capitalism works and continues to do so.