You have to compare what went before it as well. China is a success compared to the utter slavery and poverty of the common folk before the communist revolution. It's not freedom exactly, but even the US isn't free either by many measures. China has guaranteed vacation days, at least. It has near universal health insurance, and while not free, is heavily subsidized by the government.

I'd say that a perfect form of government doesn't exist, but communism isn't necessarily the worst. At least in every regard.