Oh, Eric. Not everyone on the left wants socialism or communism. Elite liberals benefit from capitalism and intend to use their social status to their advantage (H. Clinton). Under capitalism, we need government regulation to deter a corporate fascist takeover (check out Prescot Bush's Business Plot).

You're imagining communism existing in the world as is, but our current structure facilitates a power grab. Socialist policies exist right now in the US, but we have a capitalist government pursuing capitalism.

Communism and socialism aren't the same, and their philosophies won't exist in a dominant capitalist structure. We won't have a worker-owned economy until there's a revolution, so don't worry. It's not happening in our lifetime, but capitalism will fail because forever growth isn't possible. We'll likely see this happen, but I expect fascism to follow.