I wonder if anyone ever said "Democracy would never work, just look at what happened to Athens".
Socialism and communism are relatively new ideas. While I don't believe communism is an effective form of government, it's still kind of silly to write it off so quickly.
There isn't really a single form of communist government, same as there isn't a single way to do democracy or capitalism. Every country does it different, experiments a different way. For all we know, the perfect way to do it is just waiting for us to discover.
For example, I'd say the US's form of liberal, bourgeois democracy is one of the worst ways to implement it, but it was also an early experiment with it and deserves credit for at least trying it and helping us learn what to do and what not to do.
There is a poem in Polish, it goes in fast and dirty translation: "Today you scare us with communists, just as years ago, you scared our fathers with the democrat name".
The more I study history, the more I see the great wheel of humanity. Communists now, Jews in the 40s, Muslims in the early middles ages, the barbaric Gauls before Christ was even born. It never stops. The people with wisdom die off leaving remnants of their culture and ideas while the next generations tries to piece it all together.