to an anarchist/communist, collectivism is synonymous with fascism - it's the use of state power to deny rights, and is never justified, no matter what.
anarcho-communists also tend to argue that free markets are a type of collectivism, so don't pull out that canard. i know that liberals don't see it that way, but that's a different debate.
i'm just clarifying the point, in case people are confused. i'm a leftist, so i should support collectivism, right?
no. this is longstanding, and i'm not contradicting anything: if you're an anarchist, collectivists and collectivism are public enemy number one. they are the single greatest threat to human freedom, and have been since the dawn of time.