The biggest reason communism will never work is people don't actually like it.

I don't care if you point out all the ways Lenin, Marx, Mao, or Stalin did it wrong. They still tried and the attempt failed. You can talk about how communism solves poverty, inequality, and freedom all you want, but it's not a good system for either a democratic or authoritarian state. Any attempt to raise it from the dead will inevitably fail again because of human nature.