Just because you're a communist, it doesn't mean that you have to support any currently existing "communist" governments. Think about it; China uses money, has a well established chain-of-command hierarchy in the workplace, and systematically exploits its people for the benefit of the ruling elite.
In China, just like in Russia before it, the Capitalist bosses weren't so much removed from society as they were replaced by political bosses. The USSR and the PRoC weren't/aren't communist nations, they are simply what most of us anarchists refer to as "State Capitalism."
Communism is more useful as an economic system than as a method of governance. That's why there are several different types of Communism, but the two most important are:
Anarcho-Communism (also known as Council Communism, Autonomist Marxism, Libertarian Socialism, etc)
and Authoritarian Communism ('pure' Marxism, Marxism-Leninism, Maoism, etc.)
Because of all of these different flavors of communism, it's possible to support communism de jure, but not endorse any current de facto system. For more information, check out
The North Eastern Federation of Anarchist Communists