what did spock say?
he said that the individual rights of the many overpower the individual rights of the few. this is utilitarianism. it's also democracy. he did not say that the rights of the collective (the state. society. whatever.) overpower the rights of the individual, which would be collectivism.
there is some overlap in utility theory and corporatism, sure. there's overlap everywhere.
but, where an anarchist can readily embrace democracy, they would never agree that the state can take away individual rights.